 All Implemented Interfaces:
Serializable
,Comparable<BigDecimal>
BigDecimal
consists of an arbitrary precision integer
unscaled value and a 32bit
integer scale. If zero or positive,
the scale is the number of digits to the right of the decimal
point. If negative, the unscaled value of the number is multiplied
by ten to the power of the negation of the scale. The value of the
number represented by the BigDecimal
is therefore
(unscaledValue × 10^{scale})
.
The BigDecimal
class provides operations for
arithmetic, scale manipulation, rounding, comparison, hashing, and
format conversion. The toString()
method provides a
canonical representation of a BigDecimal
.
The BigDecimal
class gives its user complete control
over rounding behavior. If no rounding mode is specified and the
exact result cannot be represented, an ArithmeticException
is thrown; otherwise, calculations can be carried out to a chosen
precision and rounding mode by supplying an appropriate MathContext
object to the operation. In either case, eight
rounding modes are provided for the control of rounding.
Using the integer fields in this class (such as ROUND_HALF_UP
) to represent rounding mode is deprecated; the
enumeration values of the RoundingMode
enum
, (such
as RoundingMode.HALF_UP
) should be used instead.
When a MathContext
object is supplied with a precision
setting of 0 (for example, MathContext.UNLIMITED
),
arithmetic operations are exact, as are the arithmetic methods
which take no MathContext
object. As a corollary of
computing the exact result, the rounding mode setting of a
MathContext
object with a precision setting of 0 is not used and
thus irrelevant. In the case of divide, the exact quotient could
have an infinitely long decimal expansion; for example, 1 divided
by 3. If the quotient has a nonterminating decimal expansion and
the operation is specified to return an exact result, an
ArithmeticException
is thrown. Otherwise, the exact result of the
division is returned, as done for other operations.
When the precision setting is not 0, the rules of
BigDecimal
arithmetic are broadly compatible with selected modes
of operation of the arithmetic defined in ANSI X3.2741996 and ANSI
X3.2741996/AM 12000 (section 7.4). Unlike those standards,
BigDecimal
includes many rounding modes. Any conflicts
between these ANSI standards and the BigDecimal
specification are resolved in favor of BigDecimal
.
Since the same numerical value can have different
representations (with different scales), the rules of arithmetic
and rounding must specify both the numerical result and the scale
used in the result's representation.
The different representations of the same numerical value are
called members of the same cohort. The natural order of BigDecimal
considers members of the same cohort to be equal to each other. In
contrast, the equals
method requires both the
numerical value and representation to be the same for equality to
hold. The results of methods like scale
and unscaledValue()
will differ for numerically equal values with
different representations.
In general the rounding modes and precision setting determine
how operations return results with a limited number of digits when
the exact result has more digits (perhaps infinitely many in the
case of division and square root) than the number of digits returned.
First, the total number of digits to return is specified by the
MathContext
's precision
setting; this determines
the result's precision. The digit count starts from the
leftmost nonzero digit of the exact result. The rounding mode
determines how any discarded trailing digits affect the returned
result.
For all arithmetic operators, the operation is carried out as though an exact intermediate result were first calculated and then rounded to the number of digits specified by the precision setting (if necessary), using the selected rounding mode. If the exact result is not returned, some digit positions of the exact result are discarded. When rounding increases the magnitude of the returned result, it is possible for a new digit position to be created by a carry propagating to a leading "9" digit. For example, rounding the value 999.9 to three digits rounding up would be numerically equal to one thousand, represented as 100×10^{1}. In such cases, the new "1" is the leading digit position of the returned result.
For methods and constructors with a MathContext
parameter, if the result is inexact but the rounding mode is UNNECESSARY
, an
ArithmeticException
will be thrown.
Besides a logical exact result, each arithmetic operation has a preferred scale for representing a result. The preferred scale for each operation is listed in the table below.
Operation  Preferred Scale of Result 

Add  max(addend.scale(), augend.scale()) 
Subtract  max(minuend.scale(), subtrahend.scale()) 
Multiply  multiplier.scale() + multiplicand.scale() 
Divide  dividend.scale()  divisor.scale() 
Square root  radicand.scale()/2 
1/32
is 0.03125
.
Before rounding, the scale of the logical exact intermediate
result is the preferred scale for that operation. If the exact
numerical result cannot be represented in precision
digits, rounding selects the set of digits to return and the scale
of the result is reduced from the scale of the intermediate result
to the least scale which can represent the precision
digits actually returned. If the exact result can be represented
with at most precision
digits, the representation
of the result with the scale closest to the preferred scale is
returned. In particular, an exactly representable quotient may be
represented in fewer than precision
digits by removing
trailing zeros and decreasing the scale. For example, rounding to
three digits using the floor
rounding mode,
19/100 = 0.19 // integer=19, scale=2
but
21/110 = 0.190 // integer=190, scale=3
Note that for add, subtract, and multiply, the reduction in scale will equal the number of digit positions of the exact result which are discarded. If the rounding causes a carry propagation to create a new highorder digit position, an additional digit of the result is discarded than when no new digit position is created.
Other methods may have slightly different rounding semantics.
For example, the result of the pow
method using the
specified algorithm can
occasionally differ from the rounded mathematical result by more
than one unit in the last place, one ulp.
Two types of operations are provided for manipulating the scale
of a BigDecimal
: scaling/rounding operations and decimal
point motion operations. Scaling/rounding operations (setScale
and round
) return a
BigDecimal
whose value is approximately (or exactly) equal
to that of the operand, but whose scale or precision is the
specified value; that is, they increase or decrease the precision
of the stored number with minimal effect on its value. Decimal
point motion operations (movePointLeft
and
movePointRight
) return a
BigDecimal
created from the operand by moving the decimal
point a specified distance in the specified direction.
As a 32bit integer, the set of values for the scale is large,
but bounded. If the scale of a result would exceed the range of a
32bit integer, either by overflow or underflow, the operation may
throw an ArithmeticException
.
For the sake of brevity and clarity, pseudocode is used
throughout the descriptions of BigDecimal
methods. The
pseudocode expression (i + j)
is shorthand for "a
BigDecimal
whose value is that of the BigDecimal
i
added to that of the BigDecimal
j
." The pseudocode expression (i == j)
is
shorthand for "true
if and only if the
BigDecimal
i
represents the same value as the
BigDecimal
j
." Other pseudocode expressions
are interpreted similarly. Square brackets are used to represent
the particular BigInteger
and scale pair defining a
BigDecimal
value; for example [19, 2] is the
BigDecimal
numerically equal to 0.19 having a scale of 2.
All methods and constructors for this class throw
NullPointerException
when passed a null
object
reference for any input parameter.
 API Note:
 Care should be exercised if
BigDecimal
objects are used as keys in aSortedMap
or elements in aSortedSet
sinceBigDecimal
's natural ordering is inconsistent with equals. SeeComparable
,SortedMap
orSortedSet
for more information.Relation to IEEE 754 Decimal Arithmetic
Starting with its 2008 revision, the IEEE 754 Standard for Floatingpoint Arithmetic has covered decimal formats and operations. While there are broad similarities in the decimal arithmetic defined by IEEE 754 and by this class, there are notable differences as well. The fundamental similarity shared byBigDecimal
and IEEE 754 decimal arithmetic is the conceptual operation of computing the mathematical infinitely precise real number value of an operation and then mapping that real number to a representable decimal floatingpoint value under a rounding policy. The rounding policy is called a rounding mode forBigDecimal
and called a roundingdirection attribute in IEEE 7542019. When the exact value is not representable, the rounding policy determines which of the two representable decimal values bracketing the exact value is selected as the computed result. The notion of a preferred scale/preferred exponent is also shared by both systems.For differences, IEEE 754 includes several kinds of values not modeled by
BigDecimal
including negative zero, signed infinities, and NaN (notanumber). IEEE 754 defines formats, which are parameterized by base (binary or decimal), number of digits of precision, and exponent range. A format determines the set of representable values. Most operations accept as input one or more values of a given format and produce a result in the same format. ABigDecimal
's scale is equivalent to negating an IEEE 754 value's exponent.BigDecimal
values do not have a format in the same sense; all values have the same possible range of scale/exponent and the unscaled value has arbitrary precision. Instead, for theBigDecimal
operations taking aMathContext
parameter, if theMathContext
has a nonzero precision, the set of possible representable values for the result is determined by the precision of theMathContext
argument. For example inBigDecimal
, if a nonzero threedigit number and a nonzero fourdigit number are multiplied together in the context of aMathContext
object having a precision of three, the result will have three digits (assuming no overflow or underflow, etc.).The rounding policies implemented by
BigDecimal
operations indicated by rounding modes are a proper superset of the IEEE 754 roundingdirection attributes.BigDecimal
arithmetic will most resemble IEEE 754 decimal arithmetic if aMathContext
corresponding to an IEEE 754 decimal format, such as decimal64 or decimal128 is used to round all starting values and intermediate operations. The numerical values computed can differ if the exponent range of the IEEE 754 format being approximated is exceeded since aMathContext
does not constrain the scale ofBigDecimal
results. Operations that would generate a NaN or exact infinity, such as dividing by zero, throw anArithmeticException
inBigDecimal
arithmetic.  Since:
 1.1
 See Also:
BigInteger
,MathContext
,RoundingMode
,SortedMap
,SortedSet
, Serialized Form

Field Summary
Modifier and TypeFieldDescriptionstatic final BigDecimal
The value 1, with a scale of 0.static final int
Deprecated.static final int
Deprecated.UseRoundingMode.DOWN
instead.static final int
Deprecated.UseRoundingMode.FLOOR
instead.static final int
Deprecated.UseRoundingMode.HALF_DOWN
instead.static final int
Deprecated.UseRoundingMode.HALF_EVEN
instead.static final int
Deprecated.UseRoundingMode.HALF_UP
instead.static final int
Deprecated.UseRoundingMode.UNNECESSARY
instead.static final int
Deprecated.UseRoundingMode.UP
instead.static final BigDecimal
The value 10, with a scale of 0.static final BigDecimal
The value 0, with a scale of 0. 
Constructor Summary
ConstructorDescriptionBigDecimal(char[] in)
Translates a character array representation of aBigDecimal
into aBigDecimal
, accepting the same sequence of characters as theBigDecimal(String)
constructor.BigDecimal(char[] in, int offset, int len)
Translates a character array representation of aBigDecimal
into aBigDecimal
, accepting the same sequence of characters as theBigDecimal(String)
constructor, while allowing a subarray to be specified.BigDecimal(char[] in, int offset, int len, MathContext mc)
Translates a character array representation of aBigDecimal
into aBigDecimal
, accepting the same sequence of characters as theBigDecimal(String)
constructor, while allowing a subarray to be specified and with rounding according to the context settings.BigDecimal(char[] in, MathContext mc)
Translates a character array representation of aBigDecimal
into aBigDecimal
, accepting the same sequence of characters as theBigDecimal(String)
constructor and with rounding according to the context settings.BigDecimal(double val)
Translates adouble
into aBigDecimal
which is the exact decimal representation of thedouble
's binary floatingpoint value.BigDecimal(double val, MathContext mc)
Translates adouble
into aBigDecimal
, with rounding according to the context settings.BigDecimal(int val)
Translates anint
into aBigDecimal
.BigDecimal(int val, MathContext mc)
Translates anint
into aBigDecimal
, with rounding according to the context settings.BigDecimal(long val)
Translates along
into aBigDecimal
.BigDecimal(long val, MathContext mc)
Translates along
into aBigDecimal
, with rounding according to the context settings.BigDecimal(String val)
Translates the string representation of aBigDecimal
into aBigDecimal
.BigDecimal(String val, MathContext mc)
Translates the string representation of aBigDecimal
into aBigDecimal
, accepting the same strings as theBigDecimal(String)
constructor, with rounding according to the context settings.BigDecimal(BigInteger val)
Translates aBigInteger
into aBigDecimal
.BigDecimal(BigInteger unscaledVal, int scale)
Translates aBigInteger
unscaled value and anint
scale into aBigDecimal
.BigDecimal(BigInteger unscaledVal, int scale, MathContext mc)
Translates aBigInteger
unscaled value and anint
scale into aBigDecimal
, with rounding according to the context settings.BigDecimal(BigInteger val, MathContext mc)
Translates aBigInteger
into aBigDecimal
rounding according to the context settings. 
Method Summary
Modifier and TypeMethodDescriptionabs()
Returns aBigDecimal
whose value is the absolute value of thisBigDecimal
, and whose scale isthis.scale()
.abs(MathContext mc)
Returns aBigDecimal
whose value is the absolute value of thisBigDecimal
, with rounding according to the context settings.add(BigDecimal augend)
Returns aBigDecimal
whose value is(this + augend)
, and whose scale ismax(this.scale(), augend.scale())
.add(BigDecimal augend, MathContext mc)
Returns aBigDecimal
whose value is(this + augend)
, with rounding according to the context settings.byte
Converts thisBigDecimal
to abyte
, checking for lost information.int
compareTo(BigDecimal val)
Compares thisBigDecimal
numerically with the specifiedBigDecimal
.divide(BigDecimal divisor)
Returns aBigDecimal
whose value is(this / divisor)
, and whose preferred scale is(this.scale()  divisor.scale())
; if the exact quotient cannot be represented (because it has a nonterminating decimal expansion) anArithmeticException
is thrown.divide(BigDecimal divisor, int roundingMode)
Deprecated.The methoddivide(BigDecimal, RoundingMode)
should be used in preference to this legacy method.divide(BigDecimal divisor, int scale, int roundingMode)
Deprecated.The methoddivide(BigDecimal, int, RoundingMode)
should be used in preference to this legacy method.divide(BigDecimal divisor, int scale, RoundingMode roundingMode)
Returns aBigDecimal
whose value is(this / divisor)
, and whose scale is as specified.divide(BigDecimal divisor, MathContext mc)
Returns aBigDecimal
whose value is(this / divisor)
, with rounding according to the context settings.divide(BigDecimal divisor, RoundingMode roundingMode)
Returns aBigDecimal
whose value is(this / divisor)
, and whose scale isthis.scale()
.divideAndRemainder(BigDecimal divisor)
Returns a twoelementBigDecimal
array containing the result ofdivideToIntegralValue
followed by the result ofremainder
on the two operands.divideAndRemainder(BigDecimal divisor, MathContext mc)
Returns a twoelementBigDecimal
array containing the result ofdivideToIntegralValue
followed by the result ofremainder
on the two operands calculated with rounding according to the context settings.divideToIntegralValue(BigDecimal divisor)
Returns aBigDecimal
whose value is the integer part of the quotient(this / divisor)
rounded down.divideToIntegralValue(BigDecimal divisor, MathContext mc)
Returns aBigDecimal
whose value is the integer part of(this / divisor)
.double
Converts thisBigDecimal
to adouble
.boolean
Compares thisBigDecimal
with the specifiedObject
for equality.float
Converts thisBigDecimal
to afloat
.int
hashCode()
Returns the hash code for thisBigDecimal
.int
intValue()
Converts thisBigDecimal
to anint
.int
Converts thisBigDecimal
to anint
, checking for lost information.long
Converts thisBigDecimal
to along
.long
Converts thisBigDecimal
to along
, checking for lost information.max(BigDecimal val)
Returns the maximum of thisBigDecimal
andval
.min(BigDecimal val)
Returns the minimum of thisBigDecimal
andval
.movePointLeft(int n)
Returns aBigDecimal
which is equivalent to this one with the decimal point movedn
places to the left.movePointRight(int n)
Returns aBigDecimal
which is equivalent to this one with the decimal point movedn
places to the right.multiply(BigDecimal multiplicand)
Returns aBigDecimal
whose value is(this × multiplicand)
, and whose scale is(this.scale() + multiplicand.scale())
.multiply(BigDecimal multiplicand, MathContext mc)
Returns aBigDecimal
whose value is(this × multiplicand)
, with rounding according to the context settings.negate()
Returns aBigDecimal
whose value is(this)
, and whose scale isthis.scale()
.negate(MathContext mc)
Returns aBigDecimal
whose value is(this)
, with rounding according to the context settings.plus()
Returns aBigDecimal
whose value is(+this)
, and whose scale isthis.scale()
.plus(MathContext mc)
Returns aBigDecimal
whose value is(+this)
, with rounding according to the context settings.pow(int n)
Returns aBigDecimal
whose value is(this^{n})
, The power is computed exactly, to unlimited precision.pow(int n, MathContext mc)
Returns aBigDecimal
whose value is(this^{n})
.int
Returns the precision of thisBigDecimal
.remainder(BigDecimal divisor)
Returns aBigDecimal
whose value is(this % divisor)
.remainder(BigDecimal divisor, MathContext mc)
Returns aBigDecimal
whose value is(this % divisor)
, with rounding according to the context settings.round(MathContext mc)
Returns aBigDecimal
rounded according to theMathContext
settings.int
scale()
Returns the scale of thisBigDecimal
.scaleByPowerOfTen(int n)
Returns a BigDecimal whose numerical value is equal to (this
* 10^{n}).setScale(int newScale)
Returns aBigDecimal
whose scale is the specified value, and whose value is numerically equal to thisBigDecimal
's.setScale(int newScale, int roundingMode)
Deprecated.The methodsetScale(int, RoundingMode)
should be used in preference to this legacy method.setScale(int newScale, RoundingMode roundingMode)
Returns aBigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing thisBigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value.short
Converts thisBigDecimal
to ashort
, checking for lost information.int
signum()
Returns the signum function of thisBigDecimal
.sqrt(MathContext mc)
Returns an approximation to the square root ofthis
with rounding according to the context settings.Returns aBigDecimal
which is numerically equal to this one but with any trailing zeros removed from the representation.subtract(BigDecimal subtrahend)
Returns aBigDecimal
whose value is(this  subtrahend)
, and whose scale ismax(this.scale(), subtrahend.scale())
.subtract(BigDecimal subtrahend, MathContext mc)
Returns aBigDecimal
whose value is(this  subtrahend)
, with rounding according to the context settings.Converts thisBigDecimal
to aBigInteger
.Converts thisBigDecimal
to aBigInteger
, checking for lost information.Returns a string representation of thisBigDecimal
, using engineering notation if an exponent is needed.Returns a string representation of thisBigDecimal
without an exponent field.toString()
Returns the string representation of thisBigDecimal
, using scientific notation if an exponent is needed.ulp()
Returns the size of an ulp, a unit in the last place, of thisBigDecimal
.Returns aBigInteger
whose value is the unscaled value of thisBigDecimal
.static BigDecimal
valueOf(double val)
Translates adouble
into aBigDecimal
, using thedouble
's canonical string representation provided by theDouble.toString(double)
method.static BigDecimal
valueOf(long val)
Translates along
value into aBigDecimal
with a scale of zero.static BigDecimal
valueOf(long unscaledVal, int scale)
Translates along
unscaled value and anint
scale into aBigDecimal
.Methods declared in class java.lang.Number
byteValue, shortValue

Field Details

ZERO
The value 0, with a scale of 0. Since:
 1.5

ONE
The value 1, with a scale of 0. Since:
 1.5

TEN
The value 10, with a scale of 0. Since:
 1.5

ROUND_UP
Deprecated.UseRoundingMode.UP
instead.Rounding mode to round away from zero. Always increments the digit prior to a nonzero discarded fraction. Note that this rounding mode never decreases the magnitude of the calculated value. See Also:
 Constant Field Values

ROUND_DOWN
Deprecated.UseRoundingMode.DOWN
instead.Rounding mode to round towards zero. Never increments the digit prior to a discarded fraction (i.e., truncates). Note that this rounding mode never increases the magnitude of the calculated value. See Also:
 Constant Field Values

ROUND_CEILING
Deprecated.UseRoundingMode.CEILING
instead.Rounding mode to round towards positive infinity. If theBigDecimal
is positive, behaves as forROUND_UP
; if negative, behaves as forROUND_DOWN
. Note that this rounding mode never decreases the calculated value. See Also:
 Constant Field Values

ROUND_FLOOR
Deprecated.UseRoundingMode.FLOOR
instead.Rounding mode to round towards negative infinity. If theBigDecimal
is positive, behave as forROUND_DOWN
; if negative, behave as forROUND_UP
. Note that this rounding mode never increases the calculated value. See Also:
 Constant Field Values

ROUND_HALF_UP
Deprecated.UseRoundingMode.HALF_UP
instead.Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up. Behaves as forROUND_UP
if the discarded fraction is ≥ 0.5; otherwise, behaves as forROUND_DOWN
. Note that this is the rounding mode that most of us were taught in grade school. See Also:
 Constant Field Values

ROUND_HALF_DOWN
Deprecated.UseRoundingMode.HALF_DOWN
instead.Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down. Behaves as forROUND_UP
if the discarded fraction is > 0.5; otherwise, behaves as forROUND_DOWN
. See Also:
 Constant Field Values

ROUND_HALF_EVEN
Deprecated.UseRoundingMode.HALF_EVEN
instead.Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor. Behaves as forROUND_HALF_UP
if the digit to the left of the discarded fraction is odd; behaves as forROUND_HALF_DOWN
if it's even. Note that this is the rounding mode that minimizes cumulative error when applied repeatedly over a sequence of calculations. See Also:
 Constant Field Values

ROUND_UNNECESSARY
Deprecated.UseRoundingMode.UNNECESSARY
instead.Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary. If this rounding mode is specified on an operation that yields an inexact result, anArithmeticException
is thrown. See Also:
 Constant Field Values


Constructor Details

BigDecimal
public BigDecimal(char[] in, int offset, int len)Translates a character array representation of aBigDecimal
into aBigDecimal
, accepting the same sequence of characters as theBigDecimal(String)
constructor, while allowing a subarray to be specified. Implementation Note:
 If the sequence of characters is already available
within a character array, using this constructor is faster than
converting the
char
array to string and using theBigDecimal(String)
constructor.  Parameters:
in
char
array that is the source of characters.offset
 first character in the array to inspect.len
 number of characters to consider. Throws:
NumberFormatException
 ifin
is not a valid representation of aBigDecimal
or the defined subarray is not wholly withinin
. Since:
 1.5

BigDecimal
Translates a character array representation of aBigDecimal
into aBigDecimal
, accepting the same sequence of characters as theBigDecimal(String)
constructor, while allowing a subarray to be specified and with rounding according to the context settings. Implementation Note:
 If the sequence of characters is already available
within a character array, using this constructor is faster than
converting the
char
array to string and using theBigDecimal(String)
constructor.  Parameters:
in
char
array that is the source of characters.offset
 first character in the array to inspect.len
 number of characters to consider.mc
 the context to use. Throws:
NumberFormatException
 ifin
is not a valid representation of aBigDecimal
or the defined subarray is not wholly withinin
. Since:
 1.5

BigDecimal
public BigDecimal(char[] in)Translates a character array representation of aBigDecimal
into aBigDecimal
, accepting the same sequence of characters as theBigDecimal(String)
constructor. Implementation Note:
 If the sequence of characters is already available
as a character array, using this constructor is faster than
converting the
char
array to string and using theBigDecimal(String)
constructor.  Parameters:
in
char
array that is the source of characters. Throws:
NumberFormatException
 ifin
is not a valid representation of aBigDecimal
. Since:
 1.5

BigDecimal
Translates a character array representation of aBigDecimal
into aBigDecimal
, accepting the same sequence of characters as theBigDecimal(String)
constructor and with rounding according to the context settings. Implementation Note:
 If the sequence of characters is already available
as a character array, using this constructor is faster than
converting the
char
array to string and using theBigDecimal(String)
constructor.  Parameters:
in
char
array that is the source of characters.mc
 the context to use. Throws:
NumberFormatException
 ifin
is not a valid representation of aBigDecimal
. Since:
 1.5

BigDecimal
Translates the string representation of aBigDecimal
into aBigDecimal
. The string representation consists of an optional sign,'+'
('\u002B'
) or''
('\u002D'
), followed by a sequence of zero or more decimal digits ("the integer"), optionally followed by a fraction, optionally followed by an exponent.The fraction consists of a decimal point followed by zero or more decimal digits. The string must contain at least one digit in either the integer or the fraction. The number formed by the sign, the integer and the fraction is referred to as the significand.
The exponent consists of the character
'e'
('\u0065'
) or'E'
('\u0045'
) followed by one or more decimal digits. The value of the exponent must lie between Integer.MAX_VALUE
(Integer.MIN_VALUE
+1) andInteger.MAX_VALUE
, inclusive.More formally, the strings this constructor accepts are described by the following grammar:
 BigDecimalString:
 Sign_{opt} Significand Exponent_{opt}
 Sign:
+

 Significand:
 IntegerPart
.
FractionPart_{opt} .
FractionPart IntegerPart
 IntegerPart:
 Digits
 FractionPart:
 Digits
 Exponent:
 ExponentIndicator SignedInteger
 ExponentIndicator:
e
E
 SignedInteger:
 Sign_{opt} Digits
 Digits:
 Digit
 Digits Digit
 Digit:
 any character for which
Character.isDigit(char)
returnstrue
, including 0, 1, 2 ...
The scale of the returned
BigDecimal
will be the number of digits in the fraction, or zero if the string contains no decimal point, subject to adjustment for any exponent; if the string contains an exponent, the exponent is subtracted from the scale. The value of the resulting scale must lie betweenInteger.MIN_VALUE
andInteger.MAX_VALUE
, inclusive.The charactertodigit mapping is provided by
Character.digit(char, int)
set to convert to radix 10. The String may not contain any extraneous characters (whitespace, for example).Examples:
The value of the returnedBigDecimal
is equal to significand × 10^{ exponent}. For each string on the left, the resulting representation [BigInteger
,scale
] is shown on the right."0" [0,0] "0.00" [0,2] "123" [123,0] "123" [123,0] "1.23E3" [123,1] "1.23E+3" [123,1] "12.3E+7" [123,6] "12.0" [120,1] "12.3" [123,1] "0.00123" [123,5] "1.23E12" [123,14] "1234.5E4" [12345,5] "0E+7" [0,7] "0" [0,0]
 API Note:
 For values other than
float
anddouble
NaN and ±Infinity, this constructor is compatible with the values returned byFloat.toString(float)
andDouble.toString(double)
. This is generally the preferred way to convert afloat
ordouble
into a BigDecimal, as it doesn't suffer from the unpredictability of theBigDecimal(double)
constructor.  Parameters:
val
 String representation ofBigDecimal
. Throws:
NumberFormatException
 ifval
is not a valid representation of aBigDecimal
.

BigDecimal
Translates the string representation of aBigDecimal
into aBigDecimal
, accepting the same strings as theBigDecimal(String)
constructor, with rounding according to the context settings. Parameters:
val
 string representation of aBigDecimal
.mc
 the context to use. Throws:
NumberFormatException
 ifval
is not a valid representation of a BigDecimal. Since:
 1.5

BigDecimal
public BigDecimal(double val)Translates adouble
into aBigDecimal
which is the exact decimal representation of thedouble
's binary floatingpoint value. The scale of the returnedBigDecimal
is the smallest value such that(10^{scale} × val)
is an integer.Notes:

The results of this constructor can be somewhat unpredictable.
One might assume that writing
new BigDecimal(0.1)
in Java creates aBigDecimal
which is exactly equal to 0.1 (an unscaled value of 1, with a scale of 1), but it is actually equal to 0.1000000000000000055511151231257827021181583404541015625. This is because 0.1 cannot be represented exactly as adouble
(or, for that matter, as a binary fraction of any finite length). Thus, the value that is being passed in to the constructor is not exactly equal to 0.1, appearances notwithstanding. 
The
String
constructor, on the other hand, is perfectly predictable: writingnew BigDecimal("0.1")
creates aBigDecimal
which is exactly equal to 0.1, as one would expect. Therefore, it is generally recommended that the String constructor be used in preference to this one. 
When a
double
must be used as a source for aBigDecimal
, note that this constructor provides an exact conversion; it does not give the same result as converting thedouble
to aString
using theDouble.toString(double)
method and then using theBigDecimal(String)
constructor. To get that result, use thestatic
valueOf(double)
method.
 Parameters:
val
double
value to be converted toBigDecimal
. Throws:
NumberFormatException
 ifval
is infinite or NaN.

The results of this constructor can be somewhat unpredictable.
One might assume that writing

BigDecimal
Translates adouble
into aBigDecimal
, with rounding according to the context settings. The scale of theBigDecimal
is the smallest value such that(10^{scale} × val)
is an integer.The results of this constructor can be somewhat unpredictable and its use is generally not recommended; see the notes under the
BigDecimal(double)
constructor. Parameters:
val
double
value to be converted toBigDecimal
.mc
 the context to use. Throws:
NumberFormatException
 ifval
is infinite or NaN. Since:
 1.5

BigDecimal
Translates aBigInteger
into aBigDecimal
. The scale of theBigDecimal
is zero. Parameters:
val
BigInteger
value to be converted toBigDecimal
.

BigDecimal
Translates aBigInteger
into aBigDecimal
rounding according to the context settings. The scale of theBigDecimal
is zero. Parameters:
val
BigInteger
value to be converted toBigDecimal
.mc
 the context to use. Since:
 1.5

BigDecimal
Translates aBigInteger
unscaled value and anint
scale into aBigDecimal
. The value of theBigDecimal
is(unscaledVal × 10^{scale})
. Parameters:
unscaledVal
 unscaled value of theBigDecimal
.scale
 scale of theBigDecimal
.

BigDecimal
Translates aBigInteger
unscaled value and anint
scale into aBigDecimal
, with rounding according to the context settings. The value of theBigDecimal
is(unscaledVal × 10^{scale})
, rounded according to theprecision
and rounding mode settings. Parameters:
unscaledVal
 unscaled value of theBigDecimal
.scale
 scale of theBigDecimal
.mc
 the context to use. Since:
 1.5

BigDecimal
public BigDecimal(int val)Translates anint
into aBigDecimal
. The scale of theBigDecimal
is zero. Parameters:
val
int
value to be converted toBigDecimal
. Since:
 1.5

BigDecimal
Translates anint
into aBigDecimal
, with rounding according to the context settings. The scale of theBigDecimal
, before any rounding, is zero. Parameters:
val
int
value to be converted toBigDecimal
.mc
 the context to use. Since:
 1.5

BigDecimal
public BigDecimal(long val)Translates along
into aBigDecimal
. The scale of theBigDecimal
is zero. Parameters:
val
long
value to be converted toBigDecimal
. Since:
 1.5

BigDecimal
Translates along
into aBigDecimal
, with rounding according to the context settings. The scale of theBigDecimal
, before any rounding, is zero. Parameters:
val
long
value to be converted toBigDecimal
.mc
 the context to use. Since:
 1.5


Method Details

valueOf
Translates along
unscaled value and anint
scale into aBigDecimal
. API Note:
 This static factory method is provided in preference
to a (
long
,int
) constructor because it allows for reuse of frequently usedBigDecimal
values.  Parameters:
unscaledVal
 unscaled value of theBigDecimal
.scale
 scale of theBigDecimal
. Returns:
 a
BigDecimal
whose value is(unscaledVal × 10^{scale})
.

valueOf
Translates along
value into aBigDecimal
with a scale of zero. API Note:
 This static factory method is provided in preference
to a (
long
) constructor because it allows for reuse of frequently usedBigDecimal
values.  Parameters:
val
 value of theBigDecimal
. Returns:
 a
BigDecimal
whose value isval
.

valueOf
Translates adouble
into aBigDecimal
, using thedouble
's canonical string representation provided by theDouble.toString(double)
method. API Note:
 This is generally the preferred way to convert a
double
(orfloat
) into aBigDecimal
, as the value returned is equal to that resulting from constructing aBigDecimal
from the result of usingDouble.toString(double)
.  Parameters:
val
double
to convert to aBigDecimal
. Returns:
 a
BigDecimal
whose value is equal to or approximately equal to the value ofval
.  Throws:
NumberFormatException
 ifval
is infinite or NaN. Since:
 1.5

add
Returns aBigDecimal
whose value is(this + augend)
, and whose scale ismax(this.scale(), augend.scale())
. Parameters:
augend
 value to be added to thisBigDecimal
. Returns:
this + augend

add
Returns aBigDecimal
whose value is(this + augend)
, with rounding according to the context settings. If either number is zero and the precision setting is nonzero then the other number, rounded if necessary, is used as the result. Parameters:
augend
 value to be added to thisBigDecimal
.mc
 the context to use. Returns:
this + augend
, rounded as necessary. Since:
 1.5

subtract
Returns aBigDecimal
whose value is(this  subtrahend)
, and whose scale ismax(this.scale(), subtrahend.scale())
. Parameters:
subtrahend
 value to be subtracted from thisBigDecimal
. Returns:
this  subtrahend

subtract
Returns aBigDecimal
whose value is(this  subtrahend)
, with rounding according to the context settings. Ifsubtrahend
is zero then this, rounded if necessary, is used as the result. If this is zero then the result issubtrahend.negate(mc)
. Parameters:
subtrahend
 value to be subtracted from thisBigDecimal
.mc
 the context to use. Returns:
this  subtrahend
, rounded as necessary. Since:
 1.5

multiply
Returns aBigDecimal
whose value is(this × multiplicand)
, and whose scale is(this.scale() + multiplicand.scale())
. Parameters:
multiplicand
 value to be multiplied by thisBigDecimal
. Returns:
this * multiplicand

multiply
Returns aBigDecimal
whose value is(this × multiplicand)
, with rounding according to the context settings. Parameters:
multiplicand
 value to be multiplied by thisBigDecimal
.mc
 the context to use. Returns:
this * multiplicand
, rounded as necessary. Since:
 1.5

divide
Deprecated.The methoddivide(BigDecimal, int, RoundingMode)
should be used in preference to this legacy method.Returns aBigDecimal
whose value is(this / divisor)
, and whose scale is as specified. If rounding must be performed to generate a result with the specified scale, the specified rounding mode is applied. Parameters:
divisor
 value by which thisBigDecimal
is to be divided.scale
 scale of theBigDecimal
quotient to be returned.roundingMode
 rounding mode to apply. Returns:
this / divisor
 Throws:
ArithmeticException
 ifdivisor
is zero,roundingMode==ROUND_UNNECESSARY
and the specified scale is insufficient to represent the result of the division exactly.IllegalArgumentException
 ifroundingMode
does not represent a valid rounding mode. See Also:
ROUND_UP
,ROUND_DOWN
,ROUND_CEILING
,ROUND_FLOOR
,ROUND_HALF_UP
,ROUND_HALF_DOWN
,ROUND_HALF_EVEN
,ROUND_UNNECESSARY

divide
Returns aBigDecimal
whose value is(this / divisor)
, and whose scale is as specified. If rounding must be performed to generate a result with the specified scale, the specified rounding mode is applied. Parameters:
divisor
 value by which thisBigDecimal
is to be divided.scale
 scale of theBigDecimal
quotient to be returned.roundingMode
 rounding mode to apply. Returns:
this / divisor
 Throws:
ArithmeticException
 ifdivisor
is zero,roundingMode==RoundingMode.UNNECESSARY
and the specified scale is insufficient to represent the result of the division exactly. Since:
 1.5

divide
Deprecated.The methoddivide(BigDecimal, RoundingMode)
should be used in preference to this legacy method.Returns aBigDecimal
whose value is(this / divisor)
, and whose scale isthis.scale()
. If rounding must be performed to generate a result with the given scale, the specified rounding mode is applied. Parameters:
divisor
 value by which thisBigDecimal
is to be divided.roundingMode
 rounding mode to apply. Returns:
this / divisor
 Throws:
ArithmeticException
 ifdivisor==0
, orroundingMode==ROUND_UNNECESSARY
andthis.scale()
is insufficient to represent the result of the division exactly.IllegalArgumentException
 ifroundingMode
does not represent a valid rounding mode. See Also:
ROUND_UP
,ROUND_DOWN
,ROUND_CEILING
,ROUND_FLOOR
,ROUND_HALF_UP
,ROUND_HALF_DOWN
,ROUND_HALF_EVEN
,ROUND_UNNECESSARY

divide
Returns aBigDecimal
whose value is(this / divisor)
, and whose scale isthis.scale()
. If rounding must be performed to generate a result with the given scale, the specified rounding mode is applied. Parameters:
divisor
 value by which thisBigDecimal
is to be divided.roundingMode
 rounding mode to apply. Returns:
this / divisor
 Throws:
ArithmeticException
 ifdivisor==0
, orroundingMode==RoundingMode.UNNECESSARY
andthis.scale()
is insufficient to represent the result of the division exactly. Since:
 1.5

divide
Returns aBigDecimal
whose value is(this / divisor)
, and whose preferred scale is(this.scale()  divisor.scale())
; if the exact quotient cannot be represented (because it has a nonterminating decimal expansion) anArithmeticException
is thrown. Parameters:
divisor
 value by which thisBigDecimal
is to be divided. Returns:
this / divisor
 Throws:
ArithmeticException
 if the exact quotient does not have a terminating decimal expansion, including dividing by zero Since:
 1.5

divide
Returns aBigDecimal
whose value is(this / divisor)
, with rounding according to the context settings. Parameters:
divisor
 value by which thisBigDecimal
is to be divided.mc
 the context to use. Returns:
this / divisor
, rounded as necessary. Throws:
ArithmeticException
 if the result is inexact but the rounding mode isUNNECESSARY
ormc.precision == 0
and the quotient has a nonterminating decimal expansion,including dividing by zero Since:
 1.5

divideToIntegralValue
Returns aBigDecimal
whose value is the integer part of the quotient(this / divisor)
rounded down. The preferred scale of the result is(this.scale()  divisor.scale())
. Parameters:
divisor
 value by which thisBigDecimal
is to be divided. Returns:
 The integer part of
this / divisor
.  Throws:
ArithmeticException
 ifdivisor==0
 Since:
 1.5

divideToIntegralValue
Returns aBigDecimal
whose value is the integer part of(this / divisor)
. Since the integer part of the exact quotient does not depend on the rounding mode, the rounding mode does not affect the values returned by this method. The preferred scale of the result is(this.scale()  divisor.scale())
. AnArithmeticException
is thrown if the integer part of the exact quotient needs more thanmc.precision
digits. Parameters:
divisor
 value by which thisBigDecimal
is to be divided.mc
 the context to use. Returns:
 The integer part of
this / divisor
.  Throws:
ArithmeticException
 ifdivisor==0
ArithmeticException
 ifmc.precision
> 0 and the result requires a precision of more thanmc.precision
digits. Since:
 1.5

remainder
Returns aBigDecimal
whose value is(this % divisor)
.The remainder is given by
this.subtract(this.divideToIntegralValue(divisor).multiply(divisor))
. Note that this is not the modulo operation (the result can be negative). Parameters:
divisor
 value by which thisBigDecimal
is to be divided. Returns:
this % divisor
. Throws:
ArithmeticException
 ifdivisor==0
 Since:
 1.5

remainder
Returns aBigDecimal
whose value is(this % divisor)
, with rounding according to the context settings. TheMathContext
settings affect the implicit divide used to compute the remainder. The remainder computation itself is by definition exact. Therefore, the remainder may contain more thanmc.getPrecision()
digits.The remainder is given by
this.subtract(this.divideToIntegralValue(divisor, mc).multiply(divisor))
. Note that this is not the modulo operation (the result can be negative). Parameters:
divisor
 value by which thisBigDecimal
is to be divided.mc
 the context to use. Returns:
this % divisor
, rounded as necessary. Throws:
ArithmeticException
 ifdivisor==0
ArithmeticException
 if the result is inexact but the rounding mode isUNNECESSARY
, ormc.precision
> 0 and the result ofthis.divideToIntegralValue(divisor)
would require a precision of more thanmc.precision
digits. Since:
 1.5
 See Also:
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)

divideAndRemainder
Returns a twoelementBigDecimal
array containing the result ofdivideToIntegralValue
followed by the result ofremainder
on the two operands.Note that if both the integer quotient and remainder are needed, this method is faster than using the
divideToIntegralValue
andremainder
methods separately because the division need only be carried out once. Parameters:
divisor
 value by which thisBigDecimal
is to be divided, and the remainder computed. Returns:
 a two element
BigDecimal
array: the quotient (the result ofdivideToIntegralValue
) is the initial element and the remainder is the final element.  Throws:
ArithmeticException
 ifdivisor==0
 Since:
 1.5
 See Also:
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
,remainder(java.math.BigDecimal, java.math.MathContext)

divideAndRemainder
Returns a twoelementBigDecimal
array containing the result ofdivideToIntegralValue
followed by the result ofremainder
on the two operands calculated with rounding according to the context settings.Note that if both the integer quotient and remainder are needed, this method is faster than using the
divideToIntegralValue
andremainder
methods separately because the division need only be carried out once. Parameters:
divisor
 value by which thisBigDecimal
is to be divided, and the remainder computed.mc
 the context to use. Returns:
 a two element
BigDecimal
array: the quotient (the result ofdivideToIntegralValue
) is the initial element and the remainder is the final element.  Throws:
ArithmeticException
 ifdivisor==0
ArithmeticException
 if the result is inexact but the rounding mode isUNNECESSARY
, ormc.precision
> 0 and the result ofthis.divideToIntegralValue(divisor)
would require a precision of more thanmc.precision
digits. Since:
 1.5
 See Also:
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
,remainder(java.math.BigDecimal, java.math.MathContext)

sqrt
Returns an approximation to the square root ofthis
with rounding according to the context settings.The preferred scale of the returned result is equal to
this.scale()/2
. The value of the returned result is always within one ulp of the exact decimal value for the precision in question. If the rounding mode isHALF_UP
,HALF_DOWN
, orHALF_EVEN
, the result is within one half an ulp of the exact decimal value.Special case:
 The square root of a number numerically equal to
ZERO
is numerically equal toZERO
with a preferred scale according to the general rule above. In particular, forZERO
,ZERO.sqrt(mc).equals(ZERO)
is true with anyMathContext
as an argument.
 Parameters:
mc
 the context to use. Returns:
 the square root of
this
.  Throws:
ArithmeticException
 ifthis
is less than zero.ArithmeticException
 if an exact result is requested (mc.getPrecision()==0
) and there is no finite decimal expansion of the exact resultArithmeticException
 if(mc.getRoundingMode()==RoundingMode.UNNECESSARY
) and the exact result cannot fit inmc.getPrecision()
digits. Since:
 9
 See Also:
BigInteger.sqrt()
 The square root of a number numerically equal to

pow
Returns aBigDecimal
whose value is(this^{n})
, The power is computed exactly, to unlimited precision.The parameter
n
must be in the range 0 through 999999999, inclusive.ZERO.pow(0)
returnsONE
. Note that future releases may expand the allowable exponent range of this method. Parameters:
n
 power to raise thisBigDecimal
to. Returns:
this^{n}
 Throws:
ArithmeticException
 ifn
is out of range. Since:
 1.5

pow
Returns aBigDecimal
whose value is(this^{n})
. The current implementation uses the core algorithm defined in ANSI standard X3.2741996 with rounding according to the context settings. In general, the returned numerical value is within two ulps of the exact numerical value for the chosen precision. Note that future releases may use a different algorithm with a decreased allowable error bound and increased allowable exponent range.The X3.2741996 algorithm is:
 An
ArithmeticException
exception is thrown ifabs(n) > 999999999
mc.precision == 0
andn < 0
mc.precision > 0
andn
has more thanmc.precision
decimal digits
 if
n
is zero,ONE
is returned even ifthis
is zero, otherwise if
n
is positive, the result is calculated via the repeated squaring technique into a single accumulator. The individual multiplications with the accumulator use the same math context settings as inmc
except for a precision increased tomc.precision + elength + 1
whereelength
is the number of decimal digits inn
.  if
n
is negative, the result is calculated as ifn
were positive; this value is then divided into one using the working precision specified above.  The final value from either the positive or negative case is then rounded to the destination precision.
 if
 Parameters:
n
 power to raise thisBigDecimal
to.mc
 the context to use. Returns:
this^{n}
using the ANSI standard X3.2741996 algorithm Throws:
ArithmeticException
 if the result is inexact but the rounding mode isUNNECESSARY
, orn
is out of range. Since:
 1.5
 An

abs
Returns aBigDecimal
whose value is the absolute value of thisBigDecimal
, and whose scale isthis.scale()
. Returns:
abs(this)

abs
Returns aBigDecimal
whose value is the absolute value of thisBigDecimal
, with rounding according to the context settings. Parameters:
mc
 the context to use. Returns:
abs(this)
, rounded as necessary. Since:
 1.5

negate
Returns aBigDecimal
whose value is(this)
, and whose scale isthis.scale()
. Returns:
this
.

negate
Returns aBigDecimal
whose value is(this)
, with rounding according to the context settings. Parameters:
mc
 the context to use. Returns:
this
, rounded as necessary. Since:
 1.5

plus
Returns aBigDecimal
whose value is(+this)
, and whose scale isthis.scale()
.This method, which simply returns this
BigDecimal
is included for symmetry with the unary minus methodnegate()
. Returns:
this
. Since:
 1.5
 See Also:
negate()

plus
Returns aBigDecimal
whose value is(+this)
, with rounding according to the context settings.The effect of this method is identical to that of the
round(MathContext)
method. Parameters:
mc
 the context to use. Returns:
this
, rounded as necessary. A zero result will have a scale of 0. Since:
 1.5
 See Also:
round(MathContext)

signum
public int signum()Returns the signum function of thisBigDecimal
. Returns:
 1, 0, or 1 as the value of this
BigDecimal
is negative, zero, or positive.

scale
public int scale()Returns the scale of thisBigDecimal
. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. For example, a scale of3
means the unscaled value is multiplied by 1000. Returns:
 the scale of this
BigDecimal
.

precision
public int precision()Returns the precision of thisBigDecimal
. (The precision is the number of digits in the unscaled value.)The precision of a zero value is 1.
 Returns:
 the precision of this
BigDecimal
.  Since:
 1.5

unscaledValue
Returns aBigInteger
whose value is the unscaled value of thisBigDecimal
. (Computes(this * 10^{this.scale()})
.) Returns:
 the unscaled value of this
BigDecimal
.  Since:
 1.2

round
Returns aBigDecimal
rounded according to theMathContext
settings. If the precision setting is 0 then no rounding takes place.The effect of this method is identical to that of the
plus(MathContext)
method. Parameters:
mc
 the context to use. Returns:
 a
BigDecimal
rounded according to theMathContext
settings.  Since:
 1.5
 See Also:
plus(MathContext)

setScale
Returns aBigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing thisBigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division. API Note:
 Since BigDecimal objects are immutable, calls of
this method do not result in the original object being
modified, contrary to the usual convention of having methods
named
setX
mutate fieldX
. Instead,setScale
returns an object with the proper scale; the returned object may or may not be newly allocated.  Parameters:
newScale
 scale of theBigDecimal
value to be returned.roundingMode
 The rounding mode to apply. Returns:
 a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing thisBigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value.  Throws:
ArithmeticException
 ifroundingMode==UNNECESSARY
and the specified scaling operation would require rounding. Since:
 1.5
 See Also:
RoundingMode

setScale
Deprecated.The methodsetScale(int, RoundingMode)
should be used in preference to this legacy method.Returns aBigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing thisBigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division. API Note:
 Since BigDecimal objects are immutable, calls of
this method do not result in the original object being
modified, contrary to the usual convention of having methods
named
setX
mutate fieldX
. Instead,setScale
returns an object with the proper scale; the returned object may or may not be newly allocated.  Parameters:
newScale
 scale of theBigDecimal
value to be returned.roundingMode
 The rounding mode to apply. Returns:
 a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing thisBigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value.  Throws:
ArithmeticException
 ifroundingMode==ROUND_UNNECESSARY
and the specified scaling operation would require rounding.IllegalArgumentException
 ifroundingMode
does not represent a valid rounding mode. See Also:
ROUND_UP
,ROUND_DOWN
,ROUND_CEILING
,ROUND_FLOOR
,ROUND_HALF_UP
,ROUND_HALF_DOWN
,ROUND_HALF_EVEN
,ROUND_UNNECESSARY

setScale
Returns aBigDecimal
whose scale is the specified value, and whose value is numerically equal to thisBigDecimal
's. Throws anArithmeticException
if this is not possible.This call is typically used to increase the scale, in which case it is guaranteed that there exists a
BigDecimal
of the specified scale and the correct value. The call can also be used to reduce the scale if the caller knows that theBigDecimal
has sufficiently many zeros at the end of its fractional part (i.e., factors of ten in its integer value) to allow for the rescaling without changing its value.This method returns the same result as the twoargument versions of
setScale
, but saves the caller the trouble of specifying a rounding mode in cases where it is irrelevant. API Note:
 Since
BigDecimal
objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods namedsetX
mutate fieldX
. Instead,setScale
returns an object with the proper scale; the returned object may or may not be newly allocated.  Parameters:
newScale
 scale of theBigDecimal
value to be returned. Returns:
 a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing thisBigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value.  Throws:
ArithmeticException
 if the specified scaling operation would require rounding. See Also:
setScale(int, int)
,setScale(int, RoundingMode)

movePointLeft
Returns aBigDecimal
which is equivalent to this one with the decimal point movedn
places to the left. Ifn
is nonnegative, the call merely addsn
to the scale. Ifn
is negative, the call is equivalent tomovePointRight(n)
. TheBigDecimal
returned by this call has value(this × 10^{n})
and scalemax(this.scale()+n, 0)
. Parameters:
n
 number of places to move the decimal point to the left. Returns:
 a
BigDecimal
which is equivalent to this one with the decimal point movedn
places to the left.  Throws:
ArithmeticException
 if scale overflows.

movePointRight
Returns aBigDecimal
which is equivalent to this one with the decimal point movedn
places to the right. Ifn
is nonnegative, the call merely subtractsn
from the scale. Ifn
is negative, the call is equivalent tomovePointLeft(n)
. TheBigDecimal
returned by this call has value(this × 10^{n})
and scalemax(this.scale()n, 0)
. Parameters:
n
 number of places to move the decimal point to the right. Returns:
 a
BigDecimal
which is equivalent to this one with the decimal point movedn
places to the right.  Throws:
ArithmeticException
 if scale overflows.

scaleByPowerOfTen
Returns a BigDecimal whose numerical value is equal to (this
* 10^{n}). The scale of the result is(this.scale()  n)
. Parameters:
n
 the exponent power of ten to scale by Returns:
 a BigDecimal whose numerical value is equal to
(
this
* 10^{n})  Throws:
ArithmeticException
 if the scale would be outside the range of a 32bit integer. Since:
 1.5

stripTrailingZeros
Returns aBigDecimal
which is numerically equal to this one but with any trailing zeros removed from the representation. For example, stripping the trailing zeros from theBigDecimal
value600.0
, which has [BigInteger
,scale
] components equal to [6000, 1], yields6E2
with [BigInteger
,scale
] components equal to [6, 2]. If this BigDecimal is numerically equal to zero, thenBigDecimal.ZERO
is returned. Returns:
 a numerically equal
BigDecimal
with any trailing zeros removed.  Throws:
ArithmeticException
 if scale overflows. Since:
 1.5

compareTo
Compares thisBigDecimal
numerically with the specifiedBigDecimal
. TwoBigDecimal
objects that are equal in value but have a different scale (like 2.0 and 2.00) are considered equal by this method. Such values are in the same cohort. This method is provided in preference to individual methods for each of the six boolean comparison operators (<, ==, >, >=, !=, <=). The suggested idiom for performing these comparisons is:(x.compareTo(y)
<op>0)
, where <op> is one of the six comparison operators. Specified by:
compareTo
in interfaceComparable<BigDecimal>
 API Note:
 Note: this class has a natural ordering that is inconsistent with equals.
 Parameters:
val
BigDecimal
to which thisBigDecimal
is to be compared. Returns:
 1, 0, or 1 as this
BigDecimal
is numerically less than, equal to, or greater thanval
.

equals
Compares thisBigDecimal
with the specifiedObject
for equality. UnlikecompareTo
, this method considers twoBigDecimal
objects equal only if they are equal in value and scale. Therefore 2.0 is not equal to 2.00 when compared by this method since the former has [BigInteger
,scale
] components equal to [20, 1] while the latter has components equal to [200, 2]. Overrides:
equals
in classObject
 API Note:
 One example that shows how 2.0 and 2.00 are not
substitutable for each other under some arithmetic operations
are the two expressions:
new BigDecimal("2.0" ).divide(BigDecimal.valueOf(3), HALF_UP)
which evaluates to 0.7 and
new BigDecimal("2.00").divide(BigDecimal.valueOf(3), HALF_UP)
which evaluates to 0.67.  Parameters:
x
Object
to which thisBigDecimal
is to be compared. Returns:
true
if and only if the specifiedObject
is aBigDecimal
whose value and scale are equal to thisBigDecimal
's. See Also:
compareTo(java.math.BigDecimal)
,hashCode()

min
Returns the minimum of thisBigDecimal
andval
. Parameters:
val
 value with which the minimum is to be computed. Returns:
 the
BigDecimal
whose value is the lesser of thisBigDecimal
andval
. If they are equal, as defined by thecompareTo
method,this
is returned.  See Also:
compareTo(java.math.BigDecimal)

max
Returns the maximum of thisBigDecimal
andval
. Parameters:
val
 value with which the maximum is to be computed. Returns:
 the
BigDecimal
whose value is the greater of thisBigDecimal
andval
. If they are equal, as defined by thecompareTo
method,this
is returned.  See Also:
compareTo(java.math.BigDecimal)

hashCode
public int hashCode()Returns the hash code for thisBigDecimal
. The hash code is computed as a function of the unscaled value and the scale of thisBigDecimal
. Overrides:
hashCode
in classObject
 API Note:
 Two
BigDecimal
objects that are numerically equal but differ in scale (like 2.0 and 2.00) will generally not have the same hash code.  Returns:
 hash code for this
BigDecimal
.  See Also:
equals(Object)

toString
Returns the string representation of thisBigDecimal
, using scientific notation if an exponent is needed.A standard canonical string form of the
BigDecimal
is created as though by the following steps: first, the absolute value of the unscaled value of theBigDecimal
is converted to a string in base ten using the characters'0'
through'9'
with no leading zeros (except if its value is zero, in which case a single'0'
character is used).Next, an adjusted exponent is calculated; this is the negated scale, plus the number of characters in the converted unscaled value, less one. That is,
scale+(ulength1)
, whereulength
is the length of the absolute value of the unscaled value in decimal digits (its precision).If the scale is greater than or equal to zero and the adjusted exponent is greater than or equal to
6
, the number will be converted to a character form without using exponential notation. In this case, if the scale is zero then no decimal point is added and if the scale is positive a decimal point will be inserted with the scale specifying the number of characters to the right of the decimal point.'0'
characters are added to the left of the converted unscaled value as necessary. If no character precedes the decimal point after this insertion then a conventional'0'
character is prefixed.Otherwise (that is, if the scale is negative, or the adjusted exponent is less than
6
), the number will be converted to a character form using exponential notation. In this case, if the convertedBigInteger
has more than one digit a decimal point is inserted after the first digit. An exponent in character form is then suffixed to the converted unscaled value (perhaps with inserted decimal point); this comprises the letter'E'
followed immediately by the adjusted exponent converted to a character form. The latter is in base ten, using the characters'0'
through'9'
with no leading zeros, and is always prefixed by a sign character''
('\u002D'
) if the adjusted exponent is negative,'+'
('\u002B'
) otherwise).Finally, the entire string is prefixed by a minus sign character
''
('\u002D'
) if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive.Examples:
For each representation [unscaled value, scale] on the left, the resulting string is shown on the right.
[123,0] "123" [123,0] "123" [123,1] "1.23E+3" [123,3] "1.23E+5" [123,1] "12.3" [123,5] "0.00123" [123,10] "1.23E8" [123,12] "1.23E10"
Notes: There is a onetoone mapping between the distinguishable
BigDecimal
values and the result of this conversion. That is, every distinguishableBigDecimal
value (unscaled value and scale) has a unique string representation as a result of usingtoString
. If that string representation is converted back to aBigDecimal
using theBigDecimal(String)
constructor, then the original value will be recovered.  The string produced for a given number is always the same;
it is not affected by locale. This means that it can be used
as a canonical string representation for exchanging decimal
data, or as a key for a Hashtable, etc. Localesensitive
number formatting and parsing is handled by the
NumberFormat
class and its subclasses.  The
toEngineeringString()
method may be used for presenting numbers with exponents in engineering notation, and thesetScale
method may be used for rounding aBigDecimal
so it has a known number of digits after the decimal point.  The digittocharacter mapping provided by
Character.forDigit
is used.
 Overrides:
toString
in classObject
 Returns:
 string representation of this
BigDecimal
.  See Also:
Character.forDigit(int, int)
,BigDecimal(java.lang.String)
 There is a onetoone mapping between the distinguishable

toEngineeringString
Returns a string representation of thisBigDecimal
, using engineering notation if an exponent is needed.Returns a string that represents the
BigDecimal
as described in thetoString()
method, except that if exponential notation is used, the power of ten is adjusted to be a multiple of three (engineering notation) such that the integer part of nonzero values will be in the range 1 through 999. If exponential notation is used for zero values, a decimal point and one or two fractional zero digits are used so that the scale of the zero value is preserved. Note that unlike the output oftoString()
, the output of this method is not guaranteed to recover the same [integer, scale] pair of thisBigDecimal
if the output string is converting back to aBigDecimal
using the string constructor. The result of this method meets the weaker constraint of always producing a numerically equal result from applying the string constructor to the method's output. Returns:
 string representation of this
BigDecimal
, using engineering notation if an exponent is needed.  Since:
 1.5

toPlainString
Returns a string representation of thisBigDecimal
without an exponent field. For values with a positive scale, the number of digits to the right of the decimal point is used to indicate scale. For values with a zero or negative scale, the resulting string is generated as if the value were converted to a numerically equal value with zero scale and as if all the trailing zeros of the zero scale value were present in the result. The entire string is prefixed by a minus sign character '' ('\u002D'
) if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive. Note that if the result of this method is passed to the string constructor, only the numerical value of thisBigDecimal
will necessarily be recovered; the representation of the newBigDecimal
may have a different scale. In particular, if thisBigDecimal
has a negative scale, the string resulting from this method will have a scale of zero when processed by the string constructor. (This method behaves analogously to thetoString
method in 1.4 and earlier releases.) Returns:
 a string representation of this
BigDecimal
without an exponent field.  Since:
 1.5
 See Also:
toString()
,toEngineeringString()

toBigInteger
Converts thisBigDecimal
to aBigInteger
. This conversion is analogous to the narrowing primitive conversion fromdouble
tolong
as defined in The Java Language Specification: any fractional part of thisBigDecimal
will be discarded. Note that this conversion can lose information about the precision of theBigDecimal
value.To have an exception thrown if the conversion is inexact (in other words if a nonzero fractional part is discarded), use the
toBigIntegerExact()
method. Returns:
 this
BigDecimal
converted to aBigInteger
.  See Java Language Specification:

5.1.3 Narrowing Primitive Conversion

toBigIntegerExact
Converts thisBigDecimal
to aBigInteger
, checking for lost information. An exception is thrown if thisBigDecimal
has a nonzero fractional part. Returns:
 this
BigDecimal
converted to aBigInteger
.  Throws:
ArithmeticException
 ifthis
has a nonzero fractional part. Since:
 1.5

longValue
public long longValue()Converts thisBigDecimal
to along
. This conversion is analogous to the narrowing primitive conversion fromdouble
toshort
as defined in The Java Language Specification: any fractional part of thisBigDecimal
will be discarded, and if the resulting "BigInteger
" is too big to fit in along
, only the loworder 64 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of thisBigDecimal
value as well as return a result with the opposite sign. Specified by:
longValue
in classNumber
 Returns:
 this
BigDecimal
converted to along
.  See Java Language Specification:

5.1.3 Narrowing Primitive Conversion

longValueExact
public long longValueExact()Converts thisBigDecimal
to along
, checking for lost information. If thisBigDecimal
has a nonzero fractional part or is out of the possible range for along
result then anArithmeticException
is thrown. Returns:
 this
BigDecimal
converted to along
.  Throws:
ArithmeticException
 ifthis
has a nonzero fractional part, or will not fit in along
. Since:
 1.5

intValue
public int intValue()Converts thisBigDecimal
to anint
. This conversion is analogous to the narrowing primitive conversion fromdouble
toshort
as defined in The Java Language Specification: any fractional part of thisBigDecimal
will be discarded, and if the resulting "BigInteger
" is too big to fit in anint
, only the loworder 32 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of thisBigDecimal
value as well as return a result with the opposite sign. Specified by:
intValue
in classNumber
 Returns:
 this
BigDecimal
converted to anint
.  See Java Language Specification:

5.1.3 Narrowing Primitive Conversion

intValueExact
public int intValueExact()Converts thisBigDecimal
to anint
, checking for lost information. If thisBigDecimal
has a nonzero fractional part or is out of the possible range for anint
result then anArithmeticException
is thrown. Returns:
 this
BigDecimal
converted to anint
.  Throws:
ArithmeticException
 ifthis
has a nonzero fractional part, or will not fit in anint
. Since:
 1.5

shortValueExact
public short shortValueExact()Converts thisBigDecimal
to ashort
, checking for lost information. If thisBigDecimal
has a nonzero fractional part or is out of the possible range for ashort
result then anArithmeticException
is thrown. Returns:
 this
BigDecimal
converted to ashort
.  Throws:
ArithmeticException
 ifthis
has a nonzero fractional part, or will not fit in ashort
. Since:
 1.5

byteValueExact
public byte byteValueExact()Converts thisBigDecimal
to abyte
, checking for lost information. If thisBigDecimal
has a nonzero fractional part or is out of the possible range for abyte
result then anArithmeticException
is thrown. Returns:
 this
BigDecimal
converted to abyte
.  Throws:
ArithmeticException
 ifthis
has a nonzero fractional part, or will not fit in abyte
. Since:
 1.5

floatValue
public float floatValue()Converts thisBigDecimal
to afloat
. This conversion is similar to the narrowing primitive conversion fromdouble
tofloat
as defined in The Java Language Specification: if thisBigDecimal
has too great a magnitude to represent as afloat
, it will be converted toFloat.NEGATIVE_INFINITY
orFloat.POSITIVE_INFINITY
as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of theBigDecimal
value. Specified by:
floatValue
in classNumber
 Returns:
 this
BigDecimal
converted to afloat
.  See Java Language Specification:

5.1.3 Narrowing Primitive Conversion

doubleValue
public double doubleValue()Converts thisBigDecimal
to adouble
. This conversion is similar to the narrowing primitive conversion fromdouble
tofloat
as defined in The Java Language Specification: if thisBigDecimal
has too great a magnitude represent as adouble
, it will be converted toDouble.NEGATIVE_INFINITY
orDouble.POSITIVE_INFINITY
as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of theBigDecimal
value. Specified by:
doubleValue
in classNumber
 Returns:
 this
BigDecimal
converted to adouble
.  See Java Language Specification:

5.1.3 Narrowing Primitive Conversion

ulp
Returns the size of an ulp, a unit in the last place, of thisBigDecimal
. An ulp of a nonzeroBigDecimal
value is the positive distance between this value and theBigDecimal
value next larger in magnitude with the same number of digits. An ulp of a zero value is numerically equal to 1 with the scale ofthis
. The result is stored with the same scale asthis
so the result for zero and nonzero values is equal to[1, this.scale()]
. Returns:
 the size of an ulp of
this
 Since:
 1.5

RoundingMode.CEILING
instead.