- java.lang.Object
-
- java.lang.Number
-
- java.lang.Double
-
- All Implemented Interfaces:
Serializable
,Comparable<Double>
,Constable
,ConstantDesc
public final class Double extends Number implements Comparable<Double>, Constable, ConstantDesc
TheDouble
class wraps a value of the primitive typedouble
in an object. An object of typeDouble
contains a single field whose type isdouble
.In addition, this class provides several methods for converting a
double
to aString
and aString
to adouble
, as well as other constants and methods useful when dealing with adouble
.- Since:
- 1.0
- See Also:
- Serialized Form
-
-
Field Summary
Fields Modifier and Type Field Description static int
BYTES
The number of bytes used to represent adouble
value.static int
MAX_EXPONENT
Maximum exponent a finitedouble
variable may have.static double
MAX_VALUE
A constant holding the largest positive finite value of typedouble
, (2-2-52)·21023.static int
MIN_EXPONENT
Minimum exponent a normalizeddouble
variable may have.static double
MIN_NORMAL
A constant holding the smallest positive normal value of typedouble
, 2-1022.static double
MIN_VALUE
A constant holding the smallest positive nonzero value of typedouble
, 2-1074.static double
NaN
A constant holding a Not-a-Number (NaN) value of typedouble
.static double
NEGATIVE_INFINITY
A constant holding the negative infinity of typedouble
.static double
POSITIVE_INFINITY
A constant holding the positive infinity of typedouble
.static int
SIZE
The number of bits used to represent adouble
value.static Class<Double>
TYPE
TheClass
instance representing the primitive typedouble
.
-
Method Summary
Modifier and Type Method Description byte
byteValue()
Returns the value of thisDouble
as abyte
after a narrowing primitive conversion.static int
compare(double d1, double d2)
Compares the two specifieddouble
values.int
compareTo(Double anotherDouble)
Compares twoDouble
objects numerically.Optional<Double>
describeConstable()
Returns anOptional
containing the nominal descriptor for this instance, which is the instance itself.static long
doubleToLongBits(double value)
Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "double format" bit layout.static long
doubleToRawLongBits(double value)
Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "double format" bit layout, preserving Not-a-Number (NaN) values.double
doubleValue()
Returns thedouble
value of thisDouble
object.boolean
equals(Object obj)
Compares this object against the specified object.float
floatValue()
Returns the value of thisDouble
as afloat
after a narrowing primitive conversion.int
hashCode()
Returns a hash code for thisDouble
object.static int
hashCode(double value)
Returns a hash code for adouble
value; compatible withDouble.hashCode()
.int
intValue()
Returns the value of thisDouble
as anint
after a narrowing primitive conversion.static boolean
isFinite(double d)
Returnstrue
if the argument is a finite floating-point value; returnsfalse
otherwise (for NaN and infinity arguments).boolean
isInfinite()
Returnstrue
if thisDouble
value is infinitely large in magnitude,false
otherwise.static boolean
isInfinite(double v)
Returnstrue
if the specified number is infinitely large in magnitude,false
otherwise.boolean
isNaN()
Returnstrue
if thisDouble
value is a Not-a-Number (NaN),false
otherwise.static boolean
isNaN(double v)
Returnstrue
if the specified number is a Not-a-Number (NaN) value,false
otherwise.static double
longBitsToDouble(long bits)
Returns thedouble
value corresponding to a given bit representation.long
longValue()
Returns the value of thisDouble
as along
after a narrowing primitive conversion.static double
max(double a, double b)
Returns the greater of twodouble
values as if by callingMath.max
.static double
min(double a, double b)
Returns the smaller of twodouble
values as if by callingMath.min
.static double
parseDouble(String s)
Returns a newdouble
initialized to the value represented by the specifiedString
, as performed by thevalueOf
method of classDouble
.Double
resolveConstantDesc(MethodHandles.Lookup lookup)
Resolves this instance as aConstantDesc
, the result of which is the instance itself.short
shortValue()
Returns the value of thisDouble
as ashort
after a narrowing primitive conversion.static double
sum(double a, double b)
Adds twodouble
values together as per the + operator.static String
toHexString(double d)
Returns a hexadecimal string representation of thedouble
argument.String
toString()
Returns a string representation of thisDouble
object.static String
toString(double d)
Returns a string representation of thedouble
argument.static Double
valueOf(double d)
Returns aDouble
instance representing the specifieddouble
value.static Double
valueOf(String s)
Returns aDouble
object holding thedouble
value represented by the argument strings
.
-
-
-
Field Detail
-
POSITIVE_INFINITY
public static final double POSITIVE_INFINITY
A constant holding the positive infinity of typedouble
. It is equal to the value returned byDouble.longBitsToDouble(0x7ff0000000000000L)
.- See Also:
- Constant Field Values
-
NEGATIVE_INFINITY
public static final double NEGATIVE_INFINITY
A constant holding the negative infinity of typedouble
. It is equal to the value returned byDouble.longBitsToDouble(0xfff0000000000000L)
.- See Also:
- Constant Field Values
-
NaN
public static final double NaN
A constant holding a Not-a-Number (NaN) value of typedouble
. It is equivalent to the value returned byDouble.longBitsToDouble(0x7ff8000000000000L)
.- See Also:
- Constant Field Values
-
MAX_VALUE
public static final double MAX_VALUE
A constant holding the largest positive finite value of typedouble
, (2-2-52)·21023. It is equal to the hexadecimal floating-point literal0x1.fffffffffffffP+1023
and also equal toDouble.longBitsToDouble(0x7fefffffffffffffL)
.- See Also:
- Constant Field Values
-
MIN_NORMAL
public static final double MIN_NORMAL
A constant holding the smallest positive normal value of typedouble
, 2-1022. It is equal to the hexadecimal floating-point literal0x1.0p-1022
and also equal toDouble.longBitsToDouble(0x0010000000000000L)
.- Since:
- 1.6
- See Also:
- Constant Field Values
-
MIN_VALUE
public static final double MIN_VALUE
A constant holding the smallest positive nonzero value of typedouble
, 2-1074. It is equal to the hexadecimal floating-point literal0x0.0000000000001P-1022
and also equal toDouble.longBitsToDouble(0x1L)
.- See Also:
- Constant Field Values
-
MAX_EXPONENT
public static final int MAX_EXPONENT
Maximum exponent a finitedouble
variable may have. It is equal to the value returned byMath.getExponent(Double.MAX_VALUE)
.- Since:
- 1.6
- See Also:
- Constant Field Values
-
MIN_EXPONENT
public static final int MIN_EXPONENT
Minimum exponent a normalizeddouble
variable may have. It is equal to the value returned byMath.getExponent(Double.MIN_NORMAL)
.- Since:
- 1.6
- See Also:
- Constant Field Values
-
SIZE
public static final int SIZE
The number of bits used to represent adouble
value.- Since:
- 1.5
- See Also:
- Constant Field Values
-
BYTES
public static final int BYTES
The number of bytes used to represent adouble
value.- Since:
- 1.8
- See Also:
- Constant Field Values
-
-
Constructor Detail
-
Double
@Deprecated(since="9") public Double(double value)
Deprecated.It is rarely appropriate to use this constructor. The static factoryvalueOf(double)
is generally a better choice, as it is likely to yield significantly better space and time performance.Constructs a newly allocatedDouble
object that represents the primitivedouble
argument.- Parameters:
value
- the value to be represented by theDouble
.
-
Double
@Deprecated(since="9") public Double(String s) throws NumberFormatException
Deprecated.It is rarely appropriate to use this constructor. UseparseDouble(String)
to convert a string to adouble
primitive, or usevalueOf(String)
to convert a string to aDouble
object.Constructs a newly allocatedDouble
object that represents the floating-point value of typedouble
represented by the string. The string is converted to adouble
value as if by thevalueOf
method.- Parameters:
s
- a string to be converted to aDouble
.- Throws:
NumberFormatException
- if the string does not contain a parsable number.
-
-
Method Detail
-
toString
public static String toString(double d)
Returns a string representation of thedouble
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"
. - If m is greater than or equal to 10-3 but less
than 107, then it is represented as the integer part of
m, in decimal form with no leading zeroes, followed by
'
.
' ('\u002E'
), followed by one or more decimal digits representing the fractional part of m. - If m is less than 10-3 or greater than or
equal to 107, then it is represented in so-called
"computerized scientific notation." Let n be the unique
integer such that 10n ≤ m <
10n+1; then let a be the
mathematically exact quotient of m and
10n so that 1 ≤ a < 10. The
magnitude is then represented as the integer part of a,
as a single decimal digit, followed by '
.
' ('\u002E'
), followed by decimal digits representing the fractional part of a, followed by the letter 'E
' ('\u0045'
), followed by a representation of n as a decimal integer, as produced by the methodInteger.toString(int)
.
- If m is infinity, it is represented by the characters
double
. That is, suppose that x is the exact mathematical value represented by the decimal representation produced by this method for a finite nonzero argument d. Then d must be thedouble
value nearest to x; or if twodouble
values are equally close to x, then d must be one of them and the least significant bit of the significand of d must be0
.To create localized string representations of a floating-point value, use subclasses of
NumberFormat
.- Parameters:
d
- thedouble
to be converted.- Returns:
- a string representation of the argument.
- If the argument is NaN, the result is the string
"
-
toHexString
public static String toHexString(double d)
Returns a hexadecimal string representation of thedouble
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 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
double
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
double
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"p-1022"
. 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 Floating-point Value Hexadecimal String 1.0
0x1.0p0
-1.0
-0x1.0p0
2.0
0x1.0p1
3.0
0x1.8p1
0.5
0x1.0p-1
0.25
0x1.0p-2
Double.MAX_VALUE
0x1.fffffffffffffp1023
Minimum Normal Value
0x1.0p-1022
Maximum Subnormal Value
0x0.fffffffffffffp-1022
Double.MIN_VALUE
0x0.0000000000001p-1022
- Parameters:
d
- thedouble
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
public static Double valueOf(String s) throws NumberFormatException
Returns aDouble
object holding thedouble
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:
- Signopt
NaN
- Signopt
Infinity
- Signopt FloatingPointLiteral
- Signopt HexFloatingPointLiteral
- SignedInteger
- Signopt
- HexFloatingPointLiteral:
- HexSignificand BinaryExponent FloatTypeSuffixopt
- HexSignificand:
- HexNumeral
- HexNumeral
.
0x
HexDigitsopt.
HexDigits0X
HexDigitsopt.
HexDigits - HexNumeral
- 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 typedouble
by the usual round-to-nearest rule of IEEE 754 floating-point arithmetic, which includes preserving the sign of a zero value. Note that the round-to-nearest 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 todouble
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 aDouble
object representing thisdouble
value is returned.To interpret localized string representations of a floating-point value, use subclasses of
NumberFormat
.Note that trailing format specifiers, specifiers that determine the type of a floating-point 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 floating-point type. The two-step sequence of conversions, string tofloat
followed byfloat
todouble
, is not equivalent to converting a string directly todouble
. For example, thefloat
literal0.1f
is equal to thedouble
value0.10000000149011612
; thefloat
literal0.1f
represents a different numerical value than thedouble
literal0.1
. (The numerical value 0.1 cannot be exactly represented in a binary floating-point number.)To avoid calling this method on an invalid string and having a
NumberFormatException
be thrown, the regular expression below can be used to screen the input string:final String Digits = "(\\p{Digit}+)"; final String HexDigits = "(\\p{XDigit}+)"; // an exponent is 'e' or 'E' followed by an optionally // signed decimal integer. final String Exp = "[eE][+-]?"+Digits; final String fpRegex = ("[\\x00-\\x20]*"+ // Optional leading "whitespace" "[+-]?(" + // Optional sign character "NaN|" + // "NaN" string "Infinity|" + // "Infinity" string // A decimal floating-point string representing a finite positive // number without a leading sign has at most five basic pieces: // Digits . Digits ExponentPart FloatTypeSuffix // // Since this method allows integer-only strings as input // in addition to strings of floating-point literals, the // two sub-patterns below are simplifications of the grammar // productions from section 3.10.2 of // The Java Language Specification. // Digits ._opt Digits_opt ExponentPart_opt FloatTypeSuffix_opt "((("+Digits+"(\\.)?("+Digits+"?)("+Exp+")?)|"+ // . Digits ExponentPart_opt FloatTypeSuffix_opt "(\\.("+Digits+")("+Exp+")?)|"+ // Hexadecimal strings "((" + // 0[xX] HexDigits ._opt BinaryExponent FloatTypeSuffix_opt "(0[xX]" + HexDigits + "(\\.)?)|" + // 0[xX] HexDigits_opt . HexDigits BinaryExponent FloatTypeSuffix_opt "(0[xX]" + HexDigits + "?(\\.)" + HexDigits + ")" + ")[pP][+-]?" + Digits + "))" + "[fFdD]?))" + "[\\x00-\\x20]*");// Optional trailing "whitespace" if (Pattern.matches(fpRegex, myString)) Double.valueOf(myString); // Will not throw NumberFormatException else { // Perform suitable alternative action }
- Parameters:
s
- the string to be parsed.- Returns:
- a
Double
object holding the value represented by theString
argument. - Throws:
NumberFormatException
- if the string does not contain a parsable number.
-
valueOf
public static Double valueOf(double d)
Returns aDouble
instance representing the specifieddouble
value. If a newDouble
instance is not required, this method should generally be used in preference to the constructorDouble(double)
, as this method is likely to yield significantly better space and time performance by caching frequently requested values.- Parameters:
d
- a double value.- Returns:
- a
Double
instance representingd
. - Since:
- 1.5
-
parseDouble
public static double parseDouble(String s) throws NumberFormatException
Returns a newdouble
initialized to the value represented by the specifiedString
, as performed by thevalueOf
method of classDouble
.- Parameters:
s
- the string to be parsed.- Returns:
- the
double
value represented by the string argument. - Throws:
NullPointerException
- if the string is nullNumberFormatException
- if the string does not contain a parsabledouble
.- Since:
- 1.2
- See Also:
valueOf(String)
-
isNaN
public static boolean isNaN(double v)
Returnstrue
if the specified number is a Not-a-Number (NaN) value,false
otherwise.- Parameters:
v
- the value to be tested.- Returns:
true
if the value of the argument is NaN;false
otherwise.
-
isInfinite
public static boolean isInfinite(double v)
Returnstrue
if the specified number is infinitely large in magnitude,false
otherwise.- Parameters:
v
- the value to be tested.- Returns:
true
if the value of the argument is positive infinity or negative infinity;false
otherwise.
-
isFinite
public static boolean isFinite(double d)
Returnstrue
if the argument is a finite floating-point value; returnsfalse
otherwise (for NaN and infinity arguments).- Parameters:
d
- thedouble
value to be tested- Returns:
true
if the argument is a finite floating-point value,false
otherwise.- Since:
- 1.8
-
isNaN
public boolean isNaN()
Returnstrue
if thisDouble
value is a Not-a-Number (NaN),false
otherwise.- Returns:
true
if the value represented by this object is NaN;false
otherwise.
-
isInfinite
public boolean isInfinite()
Returnstrue
if thisDouble
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
public String toString()
Returns a string representation of thisDouble
object. The primitivedouble
value represented by this object is converted to a string exactly as if by the methodtoString
of one argument.- Overrides:
toString
in classObject
- Returns:
- a
String
representation of this object. - See Also:
toString(double)
-
byteValue
public byte byteValue()
Returns the value of thisDouble
as abyte
after a narrowing primitive conversion.
-
shortValue
public short shortValue()
Returns the value of thisDouble
as ashort
after a narrowing primitive conversion.- Overrides:
shortValue
in classNumber
- Returns:
- the
double
value represented by this object converted to typeshort
- Since:
- 1.1
- See The Java™ Language Specification:
- 5.1.3 Narrowing Primitive Conversions
-
intValue
public int intValue()
Returns the value of thisDouble
as anint
after a narrowing primitive conversion.
-
longValue
public long longValue()
Returns the value of thisDouble
as along
after a narrowing primitive conversion.
-
floatValue
public float floatValue()
Returns the value of thisDouble
as afloat
after a narrowing primitive conversion.- Specified by:
floatValue
in classNumber
- Returns:
- the
double
value represented by this object converted to typefloat
- Since:
- 1.0
- See The Java™ Language Specification:
- 5.1.3 Narrowing Primitive Conversions
-
doubleValue
public double doubleValue()
Returns thedouble
value of thisDouble
object.- Specified by:
doubleValue
in classNumber
- Returns:
- the
double
value represented by this object
-
hashCode
public int hashCode()
Returns a hash code for thisDouble
object. The result is the exclusive OR of the two halves of thelong
integer bit representation, exactly as produced by the methoddoubleToLongBits(double)
, of the primitivedouble
value represented by thisDouble
object. That is, the hash code is the value of the expression:(int)(v^(v>>>32))
v
is defined by:long v = Double.doubleToLongBits(this.doubleValue());
- Overrides:
hashCode
in classObject
- Returns:
- a
hash code
value for this object. - See Also:
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
-
hashCode
public static int hashCode(double value)
Returns a hash code for adouble
value; compatible withDouble.hashCode()
.- Parameters:
value
- the value to hash- Returns:
- a hash code value for a
double
value. - Since:
- 1.8
-
equals
public boolean equals(Object obj)
Compares this object against the specified object. The result istrue
if and only if the argument is notnull
and is aDouble
object that represents adouble
that has the same value as thedouble
represented by this object. For this purpose, twodouble
values are considered to be the same if and only if the methoddoubleToLongBits(double)
returns the identicallong
value when applied to each.Note that in most cases, for two instances of class
Double
,d1
andd2
, the value ofd1.equals(d2)
istrue
if and only ifd1.doubleValue() == d2.doubleValue()
also has the value
true
. However, there are two exceptions:- If
d1
andd2
both representDouble.NaN
, then theequals
method returnstrue
, even thoughDouble.NaN==Double.NaN
has the valuefalse
. - If
d1
represents+0.0
whiled2
represents-0.0
, or vice versa, theequal
test has the valuefalse
, even though+0.0==-0.0
has the valuetrue
.
- Overrides:
equals
in classObject
- Parameters:
obj
- the object to compare with.- Returns:
true
if the objects are the same;false
otherwise.- See Also:
doubleToLongBits(double)
- If
-
doubleToLongBits
public static long doubleToLongBits(double value)
Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "double format" bit layout.Bit 63 (the bit that is selected by the mask
0x8000000000000000L
) represents the sign of the floating-point number. Bits 62-52 (the bits that are selected by the mask0x7ff0000000000000L
) represent the exponent. Bits 51-0 (the bits that are selected by the mask0x000fffffffffffffL
) represent the significand (sometimes called the mantissa) of the floating-point number.If the argument is positive infinity, the result is
0x7ff0000000000000L
.If the argument is negative infinity, the result is
0xfff0000000000000L
.If the argument is NaN, the result is
0x7ff8000000000000L
.In all cases, the result is a
long
integer that, when given to thelongBitsToDouble(long)
method, will produce a floating-point value the same as the argument todoubleToLongBits
(except all NaN values are collapsed to a single "canonical" NaN value).- Parameters:
value
- adouble
precision floating-point number.- Returns:
- the bits that represent the floating-point number.
-
doubleToRawLongBits
public static long doubleToRawLongBits(double value)
Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "double format" bit layout, preserving Not-a-Number (NaN) values.Bit 63 (the bit that is selected by the mask
0x8000000000000000L
) represents the sign of the floating-point number. Bits 62-52 (the bits that are selected by the mask0x7ff0000000000000L
) represent the exponent. Bits 51-0 (the bits that are selected by the mask0x000fffffffffffffL
) represent the significand (sometimes called the mantissa) of the floating-point number.If the argument is positive infinity, the result is
0x7ff0000000000000L
.If the argument is negative infinity, the result is
0xfff0000000000000L
.If the argument is NaN, the result is the
long
integer representing the actual NaN value. Unlike thedoubleToLongBits
method,doubleToRawLongBits
does not collapse all the bit patterns encoding a NaN to a single "canonical" NaN value.In all cases, the result is a
long
integer that, when given to thelongBitsToDouble(long)
method, will produce a floating-point value the same as the argument todoubleToRawLongBits
.- Parameters:
value
- adouble
precision floating-point number.- Returns:
- the bits that represent the floating-point number.
- Since:
- 1.3
-
longBitsToDouble
public static double longBitsToDouble(long bits)
Returns thedouble
value corresponding to a given bit representation. The argument is considered to be a representation of a floating-point value according to the IEEE 754 floating-point "double format" bit layout.If the argument is
0x7ff0000000000000L
, the result is positive infinity.If the argument is
0xfff0000000000000L
, the result is negative infinity.If the argument is any value in the range
0x7ff0000000000001L
through0x7fffffffffffffffL
or in the range0xfff0000000000001L
through0xffffffffffffffffL
, the result is a NaN. No IEEE 754 floating-point 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 theDouble.doubleToRawLongBits
method.In all other cases, let s, e, and m be three values that can be computed from the argument:
Then the floating-point result equals the value of the mathematical expression s·m·2e-1075.int s = ((bits >> 63) == 0) ? 1 : -1; int e = (int)((bits >> 52) & 0x7ffL); long m = (e == 0) ? (bits & 0xfffffffffffffL) << 1 : (bits & 0xfffffffffffffL) | 0x10000000000000L;
Note that this method may not be able to return a
double
NaN with exactly same bit pattern as thelong
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. SolongBitsToDouble
may not be able to return adouble
with a signaling NaN bit pattern. Consequently, for somelong
values,doubleToRawLongBits(longBitsToDouble(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
- anylong
integer.- Returns:
- the
double
floating-point value with the same bit pattern.
-
compareTo
public int compareTo(Double anotherDouble)
Compares twoDouble
objects numerically. There are two ways in which comparisons performed by this method differ from those performed by the Java language numerical comparison operators (<, <=, ==, >=, >
) when applied to primitivedouble
values:-
Double.NaN
is considered by this method to be equal to itself and greater than all otherdouble
values (includingDouble.POSITIVE_INFINITY
). -
0.0d
is considered by this method to be greater than-0.0d
.
Double
objects imposed by this method is consistent with equals.- Specified by:
compareTo
in interfaceComparable<Double>
- Parameters:
anotherDouble
- theDouble
to be compared.- Returns:
- the value
0
ifanotherDouble
is numerically equal to thisDouble
; a value less than0
if thisDouble
is numerically less thananotherDouble
; and a value greater than0
if thisDouble
is numerically greater thananotherDouble
. - Since:
- 1.2
-
-
compare
public static int compare(double d1, double d2)
Compares the two specifieddouble
values. The sign of the integer value returned is the same as that of the integer that would be returned by the call:new Double(d1).compareTo(new Double(d2))
- Parameters:
d1
- the firstdouble
to compared2
- the seconddouble
to compare- Returns:
- the value
0
ifd1
is numerically equal tod2
; a value less than0
ifd1
is numerically less thand2
; and a value greater than0
ifd1
is numerically greater thand2
. - Since:
- 1.4
-
sum
public static double sum(double a, double b)
Adds twodouble
values together as per the + operator.- Parameters:
a
- the first operandb
- the second operand- Returns:
- the sum of
a
andb
- Since:
- 1.8
- See Also:
BinaryOperator
- See The Java™ Language Specification:
- 4.2.4 Floating-Point Operations
-
max
public static double max(double a, double b)
Returns the greater of twodouble
values as if by callingMath.max
.- Parameters:
a
- the first operandb
- the second operand- Returns:
- the greater of
a
andb
- Since:
- 1.8
- See Also:
BinaryOperator
-
min
public static double min(double a, double b)
Returns the smaller of twodouble
values as if by callingMath.min
.- Parameters:
a
- the first operandb
- the second operand- Returns:
- the smaller of
a
andb
. - Since:
- 1.8
- See Also:
BinaryOperator
-
describeConstable
public Optional<Double> describeConstable()
Returns anOptional
containing the nominal descriptor for this instance, which is the instance itself.- Specified by:
describeConstable
in interfaceConstable
- Returns:
- an
Optional
describing the Double instance - Since:
- 12
-
resolveConstantDesc
public Double resolveConstantDesc(MethodHandles.Lookup lookup)
Resolves this instance as aConstantDesc
, the result of which is the instance itself.- Specified by:
resolveConstantDesc
in interfaceConstantDesc
- Parameters:
lookup
- ignored- Returns:
- the Double instance
- Since:
- 12
-
-