Class Float
 All Implemented Interfaces:
Serializable
,Comparable<Float>
,Constable
,ConstantDesc
Float
class is the wrapper class for values of the primitive
type float
. An object of type Float
contains a
single field whose type is float
.
In addition, this class provides several methods for converting a
float
to a String
and a
String
to a float
, as well as other
constants and methods useful when dealing with a
float
.
This is a valuebased class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.
Floatingpoint Equality, Equivalence, and Comparison
The classjava.lang.Double
has a discussion of equality,
equivalence, and comparison of floatingpoint values that is
equally applicable to float
values.
Decimal ↔ Binary Conversion Issues
The discussion of binary to decimal conversion issues injava.lang.Double
is also
applicable to float
values. Since:
 1.0
 See Also:

Field Summary
Modifier and TypeFieldDescriptionstatic final int
The number of bytes used to represent afloat
value, 4.static final int
Maximum exponent a finitefloat
variable may have, 127.static final float
A constant holding the largest positive finite value of typefloat
, (22^{23})·2^{127}.static final int
Minimum exponent a normalizedfloat
variable may have, 126.static final float
A constant holding the smallest positive normal value of typefloat
, 2^{126}.static final float
A constant holding the smallest positive nonzero value of typefloat
, 2^{149}.static final float
A constant holding a NotaNumber (NaN) value of typefloat
.static final float
A constant holding the negative infinity of typefloat
.static final float
A constant holding the positive infinity of typefloat
.static final int
The number of bits in the significand of afloat
value, 24.static final int
The number of bits used to represent afloat
value, 32.TheClass
instance representing the primitive typefloat
. 
Constructor Summary
ConstructorDescriptionFloat
(double value) Deprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor.Float
(float value) Deprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor.Deprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor. 
Method Summary
Modifier and TypeMethodDescriptionbyte
Returns the value of thisFloat
as abyte
after a narrowing primitive conversion.static int
compare
(float f1, float f2) Compares the two specifiedfloat
values.int
Compares twoFloat
objects numerically.Returns anOptional
containing the nominal descriptor for this instance, which is the instance itself.double
Returns the value of thisFloat
as adouble
after a widening primitive conversion.boolean
Compares this object against the specified object.static float
float16ToFloat
(short floatBinary16) Returns thefloat
value closest to the numerical value of the argument, a floatingpoint binary16 value encoded in ashort
.static short
floatToFloat16
(float f) Returns the floatingpoint binary16 value, encoded in ashort
, closest in value to the argument.static int
floatToIntBits
(float value) Returns a representation of the specified floatingpoint value according to the IEEE 754 floatingpoint "single format" bit layout.static int
floatToRawIntBits
(float value) Returns a representation of the specified floatingpoint value according to the IEEE 754 floatingpoint "single format" bit layout, preserving NotaNumber (NaN) values.float
Returns thefloat
value of thisFloat
object.int
hashCode()
Returns a hash code for thisFloat
object.static int
hashCode
(float value) Returns a hash code for afloat
value; compatible withFloat.hashCode()
.static float
intBitsToFloat
(int bits) Returns thefloat
value corresponding to a given bit representation.int
intValue()
Returns the value of thisFloat
as anint
after a narrowing primitive conversion.static boolean
isFinite
(float f) Returnstrue
if the argument is a finite floatingpoint value; returnsfalse
otherwise (for NaN and infinity arguments).boolean
Returnstrue
if thisFloat
value is infinitely large in magnitude,false
otherwise.static boolean
isInfinite
(float v) Returnstrue
if the specified number is infinitely large in magnitude,false
otherwise.boolean
isNaN()
Returnstrue
if thisFloat
value is a NotaNumber (NaN),false
otherwise.static boolean
isNaN
(float v) Returnstrue
if the specified number is a NotaNumber (NaN) value,false
otherwise.long
Returns value of thisFloat
as along
after a narrowing primitive conversion.static float
max
(float a, float b) Returns the greater of twofloat
values as if by callingMath.max
.static float
min
(float a, float b) Returns the smaller of twofloat
values as if by callingMath.min
.static float
parseFloat
(String s) Returns a newfloat
initialized to the value represented by the specifiedString
, as performed by thevalueOf
method of classFloat
.Resolves this instance as aConstantDesc
, the result of which is the instance itself.short
Returns the value of thisFloat
as ashort
after a narrowing primitive conversion.static float
sum
(float a, float b) Adds twofloat
values together as per the + operator.static String
toHexString
(float f) Returns a hexadecimal string representation of thefloat
argument.toString()
Returns a string representation of thisFloat
object.static String
toString
(float f) Returns a string representation of thefloat
argument.static Float
valueOf
(float f) Returns aFloat
instance representing the specifiedfloat
value.static Float
Returns aFloat
object holding thefloat
value represented by the argument strings
.

Field Details

POSITIVE_INFINITY
public static final float POSITIVE_INFINITYA constant holding the positive infinity of typefloat
. It is equal to the value returned byFloat.intBitsToFloat(0x7f800000)
. See Also:

NEGATIVE_INFINITY
public static final float NEGATIVE_INFINITYA constant holding the negative infinity of typefloat
. It is equal to the value returned byFloat.intBitsToFloat(0xff800000)
. See Also:

NaN
public static final float NaNA constant holding a NotaNumber (NaN) value of typefloat
. It is equivalent to the value returned byFloat.intBitsToFloat(0x7fc00000)
. See Also:

MAX_VALUE
public static final float MAX_VALUEA constant holding the largest positive finite value of typefloat
, (22^{23})·2^{127}. It is equal to the hexadecimal floatingpoint literal0x1.fffffeP+127f
and also equal toFloat.intBitsToFloat(0x7f7fffff)
. See Also:

MIN_NORMAL
public static final float MIN_NORMALA constant holding the smallest positive normal value of typefloat
, 2^{126}. It is equal to the hexadecimal floatingpoint literal0x1.0p126f
and also equal toFloat.intBitsToFloat(0x00800000)
. Since:
 1.6
 See Also:

MIN_VALUE
public static final float MIN_VALUEA constant holding the smallest positive nonzero value of typefloat
, 2^{149}. It is equal to the hexadecimal floatingpoint literal0x0.000002P126f
and also equal toFloat.intBitsToFloat(0x1)
. See Also:

SIZE
public static final int SIZEThe number of bits used to represent afloat
value, 32. Since:
 1.5
 See Also:

PRECISION
public static final int PRECISIONThe number of bits in the significand of afloat
value, 24. This is the parameter N in section 4.2.3 of The Java Language Specification. Since:
 19
 See Also:

MAX_EXPONENT
public static final int MAX_EXPONENTMaximum exponent a finitefloat
variable may have, 127. It is equal to the value returned byMath.getExponent(Float.MAX_VALUE)
. Since:
 1.6
 See Also:

MIN_EXPONENT
public static final int MIN_EXPONENTMinimum exponent a normalizedfloat
variable may have, 126. It is equal to the value returned byMath.getExponent(Float.MIN_NORMAL)
. Since:
 1.6
 See Also:

BYTES
public static final int BYTESThe number of bytes used to represent afloat
value, 4. Since:
 1.8
 See Also:

TYPE


Constructor Details

Float
Deprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor. The static factoryvalueOf(float)
is generally a better choice, as it is likely to yield significantly better space and time performance.Constructs a newly allocatedFloat
object that represents the primitivefloat
argument. Parameters:
value
 the value to be represented by theFloat
.

Float
Deprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor. Instead, use the static factory methodvalueOf(float)
method as follows:Float.valueOf((float)value)
.Constructs a newly allocatedFloat
object that represents the argument converted to typefloat
. Parameters:
value
 the value to be represented by theFloat
.

Float
Deprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor. UseparseFloat(String)
to convert a string to afloat
primitive, or usevalueOf(String)
to convert a string to aFloat
object.Constructs a newly allocatedFloat
object that represents the floatingpoint value of typefloat
represented by the string. The string is converted to afloat
value as if by thevalueOf
method. Parameters:
s
 a string to be converted to aFloat
. Throws:
NumberFormatException
 if the string does not contain a parsable number.


Method Details

toString
Returns a string representation of thefloat
argument. All characters mentioned below are ASCII characters. If the argument is NaN, the result is the string
"
NaN
".  Otherwise, the result is a string that represents the sign and
magnitude (absolute value) of the argument. If the sign is
negative, the first character of the result is
'

' ('\u002D'
); if the sign is positive, no sign character appears in the result. As for the magnitude m: If m is infinity, it is represented by the characters
"Infinity"
; thus, positive infinity produces the result"Infinity"
and negative infinity produces the result"Infinity"
.  If m is zero, it is represented by the characters
"0.0"
; thus, negative zero produces the result"0.0"
and positive zero produces the result"0.0"
.  Otherwise m is positive and finite.
It is converted to a string in two stages:
 Selection of a decimal: A welldefined decimal d_{m} is selected to represent m. This decimal is (almost always) the shortest one that rounds to m according to the round to nearest rounding policy of IEEE 754 floatingpoint arithmetic.
 Formatting as a string: The decimal d_{m} is formatted as a string, either in plain or in computerized scientific notation, depending on its value.
 If m is infinity, it is represented by the characters
A decimal is a number of the form s×10^{i} for some (unique) integers s > 0 and i such that s is not a multiple of 10. These integers are the significand and the exponent, respectively, of the decimal. The length of the decimal is the (unique) positive integer n meeting 10^{n1} ≤ s < 10^{n}.
The decimal d_{m} for a finite positive m is defined as follows:
 Let R be the set of all decimals that round to m according to the usual round to nearest rounding policy of IEEE 754 floatingpoint arithmetic.
 Let p be the minimal length over all decimals in R.
 When p ≥ 2, let T be the set of all decimals in R with length p. Otherwise, let T be the set of all decimals in R with length 1 or 2.
 Define d_{m} as the decimal in T that is closest to m. Or if there are two such decimals in T, select the one with the even significand.
The (uniquely) selected decimal d_{m} is then formatted. Let s, i and n be the significand, exponent and length of d_{m}, respectively. Further, let e = n + i  1 and let s_{1}…s_{n} be the usual decimal expansion of s. Note that s_{1} ≠ 0 and s_{n} ≠ 0. Below, the decimal point
'.'
is'\u002E'
and the exponent indicator'E'
is'\u0045'
. Case 3 ≤ e < 0:
d_{m} is formatted as
0.0
…0
s_{1}…s_{n}, where there are exactly (n + i) zeroes between the decimal point and s_{1}. For example, 123 × 10^{4} is formatted as0.0123
.  Case 0 ≤ e < 7:
 Subcase i ≥ 0:
d_{m} is formatted as
s_{1}…s_{n}
0
…0.0
, where there are exactly i zeroes between s_{n} and the decimal point. For example, 123 × 10^{2} is formatted as12300.0
.  Subcase i < 0:
d_{m} is formatted as
s_{1}…s_{n+i}
.
s_{n+i+1}…s_{n}, where there are exactly i digits to the right of the decimal point. For example, 123 × 10^{1} is formatted as12.3
.
 Subcase i ≥ 0:
d_{m} is formatted as
s_{1}…s_{n}
 Case e < 3 or e ≥ 7:
computerized scientific notation is used to format
d_{m}.
Here e is formatted as by
Integer.toString(int)
. Subcase n = 1:
d_{m} is formatted as
s_{1}
.0E
e. For example, 1 × 10^{23} is formatted as1.0E23
.  Subcase n > 1:
d_{m} is formatted as
s_{1}
.
s_{2}…s_{n}E
e. For example, 123 × 10^{21} is formatted as1.23E19
.
 Subcase n = 1:
d_{m} is formatted as
s_{1}
To create localized string representations of a floatingpoint value, use subclasses of
NumberFormat
. API Note:
 This method corresponds to the general functionality of the
convertToDecimalCharacter operation defined in IEEE 754;
however, that operation is defined in terms of specifying the
number of significand digits used in the conversion.
Code to do such a conversion in the Java platform includes
converting the
float
to aBigDecimal
exactly and then rounding theBigDecimal
to the desired number of digits; sample code:floatf = 0.1f; int digits = 15; BigDecimal bd = new BigDecimal(f); String result = bd.round(new MathContext(digits, RoundingMode.HALF_UP)); // 0.100000001490116
 Parameters:
f
 thefloat
to be converted. Returns:
 a string representation of the argument.
 If the argument is NaN, the result is the string
"

toHexString
Returns a hexadecimal string representation of thefloat
argument. All characters mentioned below are ASCII characters. If the argument is NaN, the result is the string
"
NaN
".  Otherwise, the result is a string that represents the sign and
magnitude (absolute value) of the argument. If the sign is negative,
the first character of the result is '

' ('\u002D'
); if the sign is positive, no sign character appears in the result. As for the magnitude m: If m is infinity, it is represented by the string
"Infinity"
; thus, positive infinity produces the result"Infinity"
and negative infinity produces the result"Infinity"
.  If m is zero, it is represented by the string
"0x0.0p0"
; thus, negative zero produces the result"0x0.0p0"
and positive zero produces the result"0x0.0p0"
.  If m is a
float
value with a normalized representation, substrings are used to represent the significand and exponent fields. The significand is represented by the characters"0x1."
followed by a lowercase hexadecimal representation of the rest of the significand as a fraction. Trailing zeros in the hexadecimal representation are removed unless all the digits are zero, in which case a single zero is used. Next, the exponent is represented by"p"
followed by a decimal string of the unbiased exponent as if produced by a call toInteger.toString
on the exponent value.  If m is a
float
value with a subnormal representation, the significand is represented by the characters"0x0."
followed by a hexadecimal representation of the rest of the significand as a fraction. Trailing zeros in the hexadecimal representation are removed. Next, the exponent is represented by"p126"
. Note that there must be at least one nonzero digit in a subnormal significand.
 If m is infinity, it is represented by the string
Examples Floatingpoint Value Hexadecimal String 1.0
0x1.0p0
1.0
0x1.0p0
2.0
0x1.0p1
3.0
0x1.8p1
0.5
0x1.0p1
0.25
0x1.0p2
Float.MAX_VALUE
0x1.fffffep127
Minimum Normal Value
0x1.0p126
Maximum Subnormal Value
0x0.fffffep126
Float.MIN_VALUE
0x0.000002p126
 API Note:
 This method corresponds to the convertToHexCharacter operation defined in IEEE 754.
 Parameters:
f
 thefloat
to be converted. Returns:
 a hex string representation of the argument.
 Since:
 1.5
 If the argument is NaN, the result is the string
"

valueOf
Returns aFloat
object holding thefloat
value represented by the argument strings
.If
s
isnull
, then aNullPointerException
is thrown.Leading and trailing whitespace characters in
s
are ignored. Whitespace is removed as if by theString.trim()
method; that is, both ASCII space and control characters are removed. The rest ofs
should constitute a FloatValue as described by the lexical syntax rules: FloatValue:
 Sign_{opt}
NaN
 Sign_{opt}
Infinity
 Sign_{opt} FloatingPointLiteral
 Sign_{opt} HexFloatingPointLiteral
 SignedInteger
 HexFloatingPointLiteral:
 HexSignificand BinaryExponent FloatTypeSuffix_{opt}
 HexSignificand:
 HexNumeral
 HexNumeral
.
0x
HexDigits_{opt}.
HexDigits0X
HexDigits_{opt}.
HexDigits
 BinaryExponent:
 BinaryExponentIndicator SignedInteger
 BinaryExponentIndicator:
p
P
s
does not have the form of a FloatValue, then aNumberFormatException
is thrown. Otherwise,s
is regarded as representing an exact decimal value in the usual "computerized scientific notation" or as an exact hexadecimal value; this exact numerical value is then conceptually converted to an "infinitely precise" binary value that is then rounded to typefloat
by the usual roundtonearest rule of IEEE 754 floatingpoint arithmetic, which includes preserving the sign of a zero value. Note that the roundtonearest rule also implies overflow and underflow behaviour; if the exact value ofs
is large enough in magnitude (greater than or equal to (MAX_VALUE
+ulp(MAX_VALUE)
/2), rounding tofloat
will result in an infinity and if the exact value ofs
is small enough in magnitude (less than or equal toMIN_VALUE
/2), rounding to float will result in a zero. Finally, after rounding aFloat
object representing thisfloat
value is returned.Note that trailing format specifiers, specifiers that determine the type of a floatingpoint literal (
1.0f
is afloat
value;1.0d
is adouble
value), do not influence the results of this method. In other words, the numerical value of the input string is converted directly to the target floatingpoint type. In general, the twostep sequence of conversions, string todouble
followed bydouble
tofloat
, is not equivalent to converting a string directly tofloat
. For example, if first converted to an intermediatedouble
and then tofloat
, the string
"1.00000017881393421514957253748434595763683319091796875001d"
results in thefloat
value1.0000002f
; if the string is converted directly tofloat
,1.0000001f
results.To avoid calling this method on an invalid string and having a
NumberFormatException
be thrown, the documentation forDouble.valueOf
lists a regular expression which can be used to screen the input. API Note:
 To interpret localized string representations of a
floatingpoint value, or string representations that have
nonASCII digits, use
NumberFormat
. For example,NumberFormat.getInstance(l).parse(s).floatValue();
l
is the desired locale, orLocale.ROOT
if locale insensitive., This method corresponds to the convertFromDecimalCharacter and convertFromHexCharacter operations defined in IEEE 754.  Parameters:
s
 the string to be parsed. Returns:
 a
Float
object holding the value represented by theString
argument.  Throws:
NumberFormatException
 if the string does not contain a parsable number. See Also:

valueOf
Returns aFloat
instance representing the specifiedfloat
value. If a newFloat
instance is not required, this method should generally be used in preference to the constructorFloat(float)
, as this method is likely to yield significantly better space and time performance by caching frequently requested values. Parameters:
f
 a float value. Returns:
 a
Float
instance representingf
.  Since:
 1.5

parseFloat
Returns a newfloat
initialized to the value represented by the specifiedString
, as performed by thevalueOf
method of classFloat
. Parameters:
s
 the string to be parsed. Returns:
 the
float
value represented by the string argument.  Throws:
NullPointerException
 if the string is nullNumberFormatException
 if the string does not contain a parsablefloat
. Since:
 1.2
 See Also:

isNaN
public static boolean isNaN(float v) Returnstrue
if the specified number is a NotaNumber (NaN) value,false
otherwise. API Note:
 This method corresponds to the isNaN operation defined in IEEE 754.
 Parameters:
v
 the value to be tested. Returns:
true
if the argument is NaN;false
otherwise.

isInfinite
public static boolean isInfinite(float v) Returnstrue
if the specified number is infinitely large in magnitude,false
otherwise. API Note:
 This method corresponds to the isInfinite operation defined in IEEE 754.
 Parameters:
v
 the value to be tested. Returns:
true
if the argument is positive infinity or negative infinity;false
otherwise.

isFinite
public static boolean isFinite(float f) Returnstrue
if the argument is a finite floatingpoint value; returnsfalse
otherwise (for NaN and infinity arguments). API Note:
 This method corresponds to the isFinite operation defined in IEEE 754.
 Parameters:
f
 thefloat
value to be tested Returns:
true
if the argument is a finite floatingpoint value,false
otherwise. Since:
 1.8

isNaN
public boolean isNaN()Returnstrue
if thisFloat
value is a NotaNumber (NaN),false
otherwise. Returns:
true
if the value represented by this object is NaN;false
otherwise.

isInfinite
public boolean isInfinite()Returnstrue
if thisFloat
value is infinitely large in magnitude,false
otherwise. Returns:
true
if the value represented by this object is positive infinity or negative infinity;false
otherwise.

toString
Returns a string representation of thisFloat
object. The primitivefloat
value represented by this object is converted to aString
exactly as if by the methodtoString
of one argument. 
byteValue
public byte byteValue()Returns the value of thisFloat
as abyte
after a narrowing primitive conversion. Overrides:
byteValue
in classNumber
 Returns:
 the
float
value represented by this object converted to typebyte
 See Java Language Specification:

5.1.3 Narrowing Primitive Conversion

shortValue
public short shortValue()Returns the value of thisFloat
as ashort
after a narrowing primitive conversion. Overrides:
shortValue
in classNumber
 Returns:
 the
float
value represented by this object converted to typeshort
 See Java Language Specification:

5.1.3 Narrowing Primitive Conversion
 Since:
 1.1

intValue
public int intValue()Returns the value of thisFloat
as anint
after a narrowing primitive conversion. Specified by:
intValue
in classNumber
 API Note:
 This method corresponds to the convertToIntegerTowardZero operation defined in IEEE 754.
 Returns:
 the
float
value represented by this object converted to typeint
 See Java Language Specification:

5.1.3 Narrowing Primitive Conversion

longValue
public long longValue()Returns value of thisFloat
as along
after a narrowing primitive conversion. Specified by:
longValue
in classNumber
 API Note:
 This method corresponds to the convertToIntegerTowardZero operation defined in IEEE 754.
 Returns:
 the
float
value represented by this object converted to typelong
 See Java Language Specification:

5.1.3 Narrowing Primitive Conversion

floatValue
public float floatValue()Returns thefloat
value of thisFloat
object. Specified by:
floatValue
in classNumber
 Returns:
 the
float
value represented by this object

doubleValue
public double doubleValue()Returns the value of thisFloat
as adouble
after a widening primitive conversion. Specified by:
doubleValue
in classNumber
 API Note:
 This method corresponds to the convertFormat operation defined in IEEE 754.
 Returns:
 the
float
value represented by this object converted to typedouble
 See Java Language Specification:

5.1.2 Widening Primitive Conversion

hashCode
public int hashCode()Returns a hash code for thisFloat
object. The result is the integer bit representation, exactly as produced by the methodfloatToIntBits(float)
, of the primitivefloat
value represented by thisFloat
object. 
hashCode
public static int hashCode(float value) Returns a hash code for afloat
value; compatible withFloat.hashCode()
. Parameters:
value
 the value to hash Returns:
 a hash code value for a
float
value.  Since:
 1.8

equals
Compares this object against the specified object. The result istrue
if and only if the argument is notnull
and is aFloat
object that represents afloat
with the same value as thefloat
represented by this object. For this purpose, twofloat
values are considered to be the same if and only if the methodfloatToIntBits(float)
returns the identicalint
value when applied to each. Overrides:
equals
in classObject
 API Note:
 This method is defined in terms of
floatToIntBits(float)
rather than the==
operator onfloat
values since the==
operator does not define an equivalence relation and to satisfy the equals contract an equivalence relation must be implemented; see this discussion for details of floatingpoint equality and equivalence.  Parameters:
obj
 the object to be compared Returns:
true
if the objects are the same;false
otherwise. See Java Language Specification:

15.21.1 Numerical Equality Operators == and !=
 See Also:

floatToIntBits
public static int floatToIntBits(float value) Returns a representation of the specified floatingpoint value according to the IEEE 754 floatingpoint "single format" bit layout.Bit 31 (the bit that is selected by the mask
0x80000000
) represents the sign of the floatingpoint number. Bits 3023 (the bits that are selected by the mask0x7f800000
) represent the exponent. Bits 220 (the bits that are selected by the mask0x007fffff
) represent the significand (sometimes called the mantissa) of the floatingpoint number.If the argument is positive infinity, the result is
0x7f800000
.If the argument is negative infinity, the result is
0xff800000
.If the argument is NaN, the result is
0x7fc00000
.In all cases, the result is an integer that, when given to the
intBitsToFloat(int)
method, will produce a floatingpoint value the same as the argument tofloatToIntBits
(except all NaN values are collapsed to a single "canonical" NaN value). Parameters:
value
 a floatingpoint number. Returns:
 the bits that represent the floatingpoint number.

floatToRawIntBits
public static int floatToRawIntBits(float value) Returns a representation of the specified floatingpoint value according to the IEEE 754 floatingpoint "single format" bit layout, preserving NotaNumber (NaN) values.Bit 31 (the bit that is selected by the mask
0x80000000
) represents the sign of the floatingpoint number. Bits 3023 (the bits that are selected by the mask0x7f800000
) represent the exponent. Bits 220 (the bits that are selected by the mask0x007fffff
) represent the significand (sometimes called the mantissa) of the floatingpoint number.If the argument is positive infinity, the result is
0x7f800000
.If the argument is negative infinity, the result is
0xff800000
.If the argument is NaN, the result is the integer representing the actual NaN value. Unlike the
floatToIntBits
method,floatToRawIntBits
does not collapse all the bit patterns encoding a NaN to a single "canonical" NaN value.In all cases, the result is an integer that, when given to the
intBitsToFloat(int)
method, will produce a floatingpoint value the same as the argument tofloatToRawIntBits
. Parameters:
value
 a floatingpoint number. Returns:
 the bits that represent the floatingpoint number.
 Since:
 1.3

intBitsToFloat
public static float intBitsToFloat(int bits) Returns thefloat
value corresponding to a given bit representation. The argument is considered to be a representation of a floatingpoint value according to the IEEE 754 floatingpoint "single format" bit layout.If the argument is
0x7f800000
, the result is positive infinity.If the argument is
0xff800000
, the result is negative infinity.If the argument is any value in the range
0x7f800001
through0x7fffffff
or in the range0xff800001
through0xffffffff
, the result is a NaN. No IEEE 754 floatingpoint operation provided by Java can distinguish between two NaN values of the same type with different bit patterns. Distinct values of NaN are only distinguishable by use of theFloat.floatToRawIntBits
method.In all other cases, let s, e, and m be three values that can be computed from the argument:
int s = ((bits >> 31) == 0) ? 1 : 1; int e = ((bits >> 23) & 0xff); int m = (e == 0) ? (bits & 0x7fffff) << 1 : (bits & 0x7fffff)  0x800000;
Note that this method may not be able to return a
float
NaN with exactly same bit pattern as theint
argument. IEEE 754 distinguishes between two kinds of NaNs, quiet NaNs and signaling NaNs. The differences between the two kinds of NaN are generally not visible in Java. Arithmetic operations on signaling NaNs turn them into quiet NaNs with a different, but often similar, bit pattern. However, on some processors merely copying a signaling NaN also performs that conversion. In particular, copying a signaling NaN to return it to the calling method may perform this conversion. SointBitsToFloat
may not be able to return afloat
with a signaling NaN bit pattern. Consequently, for someint
values,floatToRawIntBits(intBitsToFloat(start))
may not equalstart
. Moreover, which particular bit patterns represent signaling NaNs is platform dependent; although all NaN bit patterns, quiet or signaling, must be in the NaN range identified above. Parameters:
bits
 an integer. Returns:
 the
float
floatingpoint value with the same bit pattern.

float16ToFloat
public static float float16ToFloat(short floatBinary16) Returns thefloat
value closest to the numerical value of the argument, a floatingpoint binary16 value encoded in ashort
. The conversion is exact; all binary16 values can be exactly represented infloat
. Special cases: If the argument is zero, the result is a zero with the same sign as the argument.
 If the argument is infinite, the result is an infinity with the same sign as the argument.
 If the argument is a NaN, the result is a NaN.
IEEE 754 binary16 format
The IEEE 754 standard defines binary16 as a 16bit format, along with the 32bit binary32 format (corresponding to thefloat
type) and the 64bit binary64 format (corresponding to thedouble
type). The binary16 format is similar to the other IEEE 754 formats, except smaller, having all the usual IEEE 754 values such as NaN, signed infinities, signed zeros, and subnormals. The parameters (JLS 4.2.3) for the binary16 format are N = 11 precision bits, K = 5 exponent bits, E_{max} = 15, and E_{min} = 14. API Note:
 This method corresponds to the convertFormat operation defined in IEEE 754 from the binary16 format to the binary32 format. The operation of this method is analogous to a primitive widening conversion (JLS 5.1.2).
 Parameters:
floatBinary16
 the binary16 value to convert tofloat
 Returns:
 the
float
value closest to the numerical value of the argument, a floatingpoint binary16 value encoded in ashort
 Since:
 20

floatToFloat16
public static short floatToFloat16(float f) Returns the floatingpoint binary16 value, encoded in ashort
, closest in value to the argument. The conversion is computed under the round to nearest even rounding mode. Special cases: If the argument is zero, the result is a zero with the same sign as the argument.
 If the argument is infinite, the result is an infinity with the same sign as the argument.
 If the argument is a NaN, the result is a NaN.
float16ToFloat(short)
method. API Note:
 This method corresponds to the convertFormat operation defined in IEEE 754 from the binary32 format to the binary16 format. The operation of this method is analogous to a primitive narrowing conversion (JLS 5.1.3).
 Parameters:
f
 thefloat
value to convert to binary16 Returns:
 the floatingpoint binary16 value, encoded in a
short
, closest in value to the argument  Since:
 20

compareTo
Compares twoFloat
objects numerically. This method imposes a total order onFloat
objects with two differences compared to the incomplete order defined by the Java language numerical comparison operators (<, <=, ==, >=, >
) onfloat
values. A NaN is unordered with respect to other
values and unequal to itself under the comparison
operators. This method chooses to define
Float.NaN
to be equal to itself and greater than all otherdouble
values (includingFloat.POSITIVE_INFINITY
).  Positive zero and negative zero compare equal
numerically, but are distinct and distinguishable values.
This method chooses to define positive zero (
+0.0f
), to be greater than negative zero (0.0f
).
Float
objects imposed by this method is consistent with equals; see this discussion for details of floatingpoint comparison and ordering. Specified by:
compareTo
in interfaceComparable<Float>
 Parameters:
anotherFloat
 theFloat
to be compared. Returns:
 the value
0
ifanotherFloat
is numerically equal to thisFloat
; a value less than0
if thisFloat
is numerically less thananotherFloat
; and a value greater than0
if thisFloat
is numerically greater thananotherFloat
.  See Java Language Specification:

15.20.1 Numerical Comparison Operators
<
,<=
,>
, and>=
 Since:
 1.2
 A NaN is unordered with respect to other
values and unequal to itself under the comparison
operators. This method chooses to define

compare
public static int compare(float f1, float f2) Compares the two specifiedfloat
values. The sign of the integer value returned is the same as that of the integer that would be returned by the call:Float.valueOf(f1).compareTo(Float.valueOf(f2))
 Parameters:
f1
 the firstfloat
to compare.f2
 the secondfloat
to compare. Returns:
 the value
0
iff1
is numerically equal tof2
; a value less than0
iff1
is numerically less thanf2
; and a value greater than0
iff1
is numerically greater thanf2
.  Since:
 1.4

sum
public static float sum(float a, float b) Adds twofloat
values together as per the + operator. API Note:
 This method corresponds to the addition operation defined in IEEE 754.
 Parameters:
a
 the first operandb
 the second operand Returns:
 the sum of
a
andb
 See Java Language Specification:

4.2.4 FloatingPoint Operations
 Since:
 1.8
 See Also:

max
public static float max(float a, float b) Returns the greater of twofloat
values as if by callingMath.max
. API Note:
 This method corresponds to the maximum operation defined in IEEE 754.
 Parameters:
a
 the first operandb
 the second operand Returns:
 the greater of
a
andb
 Since:
 1.8
 See Also:

min
public static float min(float a, float b) Returns the smaller of twofloat
values as if by callingMath.min
. API Note:
 This method corresponds to the minimum operation defined in IEEE 754.
 Parameters:
a
 the first operandb
 the second operand Returns:
 the smaller of
a
andb
 Since:
 1.8
 See Also:

describeConstable

resolveConstantDesc
Resolves this instance as aConstantDesc
, the result of which is the instance itself. Specified by:
resolveConstantDesc
in interfaceConstantDesc
 Parameters:
lookup
 ignored Returns:
 the Float instance
 Since:
 12
