- All Implemented Interfaces:
- Serializable,- Comparable<Long>,- Constable,- ConstantDesc
Long class wraps a value of the primitive type 
 long in an object. An object of type Long contains a
 single field whose type is long.
  In addition, this class provides several methods for converting
 a long to a String and a String to a 
 long, as well as other constants and methods useful when dealing
 with a long.
 
This is a value-based 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.
Implementation note: The implementations of the "bit twiddling"
 methods (such as highestOneBit and
 numberOfTrailingZeros) are
 based on material from Henry S. Warren, Jr.'s Hacker's
 Delight, (Addison Wesley, 2002).
- Since:
- 1.0
- See Also:
- 
Field SummaryFieldsModifier and TypeFieldDescriptionstatic final intThe number of bytes used to represent alongvalue in two's complement binary form.static final longA constant holding the maximum value alongcan have, 263-1.static final longA constant holding the minimum value alongcan have, -263.static final intThe number of bits used to represent alongvalue in two's complement binary form.TheClassinstance representing the primitive typelong.
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Constructor SummaryConstructorsConstructorDescriptionLong(long 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.
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Method SummaryModifier and TypeMethodDescriptionstatic intbitCount(long i) Returns the number of one-bits in the two's complement binary representation of the specifiedlongvalue.byteReturns the value of thisLongas abyteafter a narrowing primitive conversion.static intcompare(long x, long y) Compares twolongvalues numerically.intCompares twoLongobjects numerically.static intcompareUnsigned(long x, long y) Compares twolongvalues numerically treating the values as unsigned.static LongDecodes aStringinto aLong.Returns anOptionalcontaining the nominal descriptor for this instance, which is the instance itself.static longdivideUnsigned(long dividend, long divisor) Returns the unsigned quotient of dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.doubleReturns the value of thisLongas adoubleafter a widening primitive conversion.booleanCompares this object to the specified object.floatReturns the value of thisLongas afloatafter a widening primitive conversion.static LongDetermines thelongvalue of the system property with the specified name.static LongDetermines thelongvalue of the system property with the specified name.static LongReturns thelongvalue of the system property with the specified name.inthashCode()Returns a hash code for thisLong.static inthashCode(long value) Returns a hash code for alongvalue; compatible withLong.hashCode().static longhighestOneBit(long i) Returns alongvalue with at most a single one-bit, in the position of the highest-order ("leftmost") one-bit in the specifiedlongvalue.intintValue()Returns the value of thisLongas anintafter a narrowing primitive conversion.longReturns the value of thisLongas alongvalue.static longlowestOneBit(long i) Returns alongvalue with at most a single one-bit, in the position of the lowest-order ("rightmost") one-bit in the specifiedlongvalue.static longmax(long a, long b) Returns the greater of twolongvalues as if by callingMath.max.static longmin(long a, long b) Returns the smaller of twolongvalues as if by callingMath.min.static intnumberOfLeadingZeros(long i) Returns the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specifiedlongvalue.static intnumberOfTrailingZeros(long i) Returns the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specifiedlongvalue.static longparseLong(CharSequence s, int beginIndex, int endIndex, int radix) Parses theCharSequenceargument as a signedlongin the specifiedradix, beginning at the specifiedbeginIndexand extending toendIndex - 1.static longParses the string argument as a signed decimallong.static longParses the string argument as a signedlongin the radix specified by the second argument.static longparseUnsignedLong(CharSequence s, int beginIndex, int endIndex, int radix) Parses theCharSequenceargument as an unsignedlongin the specifiedradix, beginning at the specifiedbeginIndexand extending toendIndex - 1.static longParses the string argument as an unsigned decimallong.static longparseUnsignedLong(String s, int radix) Parses the string argument as an unsignedlongin the radix specified by the second argument.static longremainderUnsigned(long dividend, long divisor) Returns the unsigned remainder from dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.Resolves this instance as aConstantDesc, the result of which is the instance itself.static longreverse(long i) Returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specifiedlongvalue.static longreverseBytes(long i) Returns the value obtained by reversing the order of the bytes in the two's complement representation of the specifiedlongvalue.static longrotateLeft(long i, int distance) Returns the value obtained by rotating the two's complement binary representation of the specifiedlongvalue left by the specified number of bits.static longrotateRight(long i, int distance) Returns the value obtained by rotating the two's complement binary representation of the specifiedlongvalue right by the specified number of bits.shortReturns the value of thisLongas ashortafter a narrowing primitive conversion.static intsignum(long i) Returns the signum function of the specifiedlongvalue.static longsum(long a, long b) Adds twolongvalues together as per the + operator.static StringtoBinaryString(long i) Returns a string representation of thelongargument as an unsigned integer in base 2.static StringtoHexString(long i) Returns a string representation of thelongargument as an unsigned integer in base 16.static StringtoOctalString(long i) Returns a string representation of thelongargument as an unsigned integer in base 8.toString()Returns aStringobject representing thisLong's value.static StringtoString(long i) Returns aStringobject representing the specifiedlong.static StringtoString(long i, int radix) Returns a string representation of the first argument in the radix specified by the second argument.static StringtoUnsignedString(long i) Returns a string representation of the argument as an unsigned decimal value.static StringtoUnsignedString(long i, int radix) Returns a string representation of the first argument as an unsigned integer value in the radix specified by the second argument.static LongvalueOf(long l) Returns aLonginstance representing the specifiedlongvalue.static LongReturns aLongobject holding the value of the specifiedString.static LongReturns aLongobject holding the value extracted from the specifiedStringwhen parsed with the radix given by the second argument.
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Field Details- 
MIN_VALUEA constant holding the minimum value alongcan have, -263.- See Also:
 
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MAX_VALUEA constant holding the maximum value alongcan have, 263-1.- See Also:
 
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TYPETheClassinstance representing the primitive typelong.- Since:
- 1.1
 
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SIZEThe number of bits used to represent alongvalue in two's complement binary form.- Since:
- 1.5
- See Also:
 
- 
BYTESpublic static final int BYTESThe number of bytes used to represent alongvalue in two's complement binary form.- Since:
- 1.8
- See Also:
 
 
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- 
Constructor Details- 
LongDeprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor. The static factoryvalueOf(long)is generally a better choice, as it is likely to yield significantly better space and time performance.Constructs a newly allocatedLongobject that represents the specifiedlongargument.- Parameters:
- value- the value to be represented by the- Longobject.
 
- 
LongDeprecated, for removal: This API element is subject to removal in a future version.It is rarely appropriate to use this constructor. UseparseLong(String)to convert a string to alongprimitive, or usevalueOf(String)to convert a string to aLongobject.Constructs a newly allocatedLongobject that represents thelongvalue indicated by theStringparameter. The string is converted to alongvalue in exactly the manner used by theparseLongmethod for radix 10.- Parameters:
- s- the- Stringto be converted to a- Long.
- Throws:
- NumberFormatException- if the- Stringdoes not contain a parsable- long.
 
 
- 
- 
Method Details- 
toStringReturns a string representation of the first argument in the radix specified by the second argument.If the radix is smaller than Character.MIN_RADIXor larger thanCharacter.MAX_RADIX, then the radix10is used instead.If the first argument is negative, the first element of the result is the ASCII minus sign '-'('\u002d'). If the first argument is not negative, no sign character appears in the result.The remaining characters of the result represent the magnitude of the first argument. If the magnitude is zero, it is represented by a single zero character '0'('\u0030'); otherwise, the first character of the representation of the magnitude will not be the zero character. The following ASCII characters are used as digits:
 These are0123456789abcdefghijklmnopqrstuvwxyz'\u0030'through'\u0039'and'\u0061'through'\u007a'. Ifradixis N, then the first N of these characters are used as radix-N digits in the order shown. Thus, the digits for hexadecimal (radix 16) are0123456789abcdef. If uppercase letters are desired, theString.toUpperCase()method may be called on the result:Long.toString(n, 16).toUpperCase()- Parameters:
- i- a- longto be converted to a string.
- radix- the radix to use in the string representation.
- Returns:
- a string representation of the argument in the specified radix.
- See Also:
 
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toUnsignedStringReturns a string representation of the first argument as an unsigned integer value in the radix specified by the second argument.If the radix is smaller than Character.MIN_RADIXor larger thanCharacter.MAX_RADIX, then the radix10is used instead.Note that since the first argument is treated as an unsigned value, no leading sign character is printed. If the magnitude is zero, it is represented by a single zero character '0'('\u0030'); otherwise, the first character of the representation of the magnitude will not be the zero character.The behavior of radixes and the characters used as digits are the same as toString.- Parameters:
- i- an integer to be converted to an unsigned string.
- radix- the radix to use in the string representation.
- Returns:
- an unsigned string representation of the argument in the specified radix.
- Since:
- 1.8
- See Also:
 
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toHexStringReturns a string representation of thelongargument as an unsigned integer in base 16.The unsigned longvalue is the argument plus 264 if the argument is negative; otherwise, it is equal to the argument. This value is converted to a string of ASCII digits in hexadecimal (base 16) with no extra leading0s.The value of the argument can be recovered from the returned string sby callingLong.parseUnsignedLong(s, 16).If the unsigned magnitude is zero, it is represented by a single zero character '0'('\u0030'); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The following characters are used as hexadecimal digits:
 These are the characters0123456789abcdef'\u0030'through'\u0039'and'\u0061'through'\u0066'. If uppercase letters are desired, theString.toUpperCase()method may be called on the result:Long.toHexString(n).toUpperCase()- API Note:
- The HexFormatclass provides formatting and parsing of byte arrays and primitives to return a string or adding to anAppendable.HexFormatformats and parses uppercase or lowercase hexadecimal characters, with leading zeros and for byte arrays includes for each byte a delimiter, prefix, and suffix.
- Parameters:
- i- a- longto be converted to a string.
- Returns:
- the string representation of the unsigned longvalue represented by the argument in hexadecimal (base 16).
- Since:
- 1.0.2
- See Also:
 
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toOctalStringReturns a string representation of thelongargument as an unsigned integer in base 8.The unsigned longvalue is the argument plus 264 if the argument is negative; otherwise, it is equal to the argument. This value is converted to a string of ASCII digits in octal (base 8) with no extra leading0s.The value of the argument can be recovered from the returned string sby callingLong.parseUnsignedLong(s, 8).If the unsigned magnitude is zero, it is represented by a single zero character '0'('\u0030'); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The following characters are used as octal digits:
 These are the characters01234567'\u0030'through'\u0037'.- Parameters:
- i- a- longto be converted to a string.
- Returns:
- the string representation of the unsigned longvalue represented by the argument in octal (base 8).
- Since:
- 1.0.2
- See Also:
 
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toBinaryStringReturns a string representation of thelongargument as an unsigned integer in base 2.The unsigned longvalue is the argument plus 264 if the argument is negative; otherwise, it is equal to the argument. This value is converted to a string of ASCII digits in binary (base 2) with no extra leading0s.The value of the argument can be recovered from the returned string sby callingLong.parseUnsignedLong(s, 2).If the unsigned magnitude is zero, it is represented by a single zero character '0'('\u0030'); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The characters'0'('\u0030') and'1'('\u0031') are used as binary digits.- Parameters:
- i- a- longto be converted to a string.
- Returns:
- the string representation of the unsigned longvalue represented by the argument in binary (base 2).
- Since:
- 1.0.2
- See Also:
 
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toStringReturns aStringobject representing the specifiedlong. The argument is converted to signed decimal representation and returned as a string, exactly as if the argument and the radix 10 were given as arguments to thetoString(long, int)method.- Parameters:
- i- a- longto be converted.
- Returns:
- a string representation of the argument in base 10.
 
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toUnsignedStringReturns a string representation of the argument as an unsigned decimal value. The argument is converted to unsigned decimal representation and returned as a string exactly as if the argument and radix 10 were given as arguments to thetoUnsignedString(long, int)method.- Parameters:
- i- an integer to be converted to an unsigned string.
- Returns:
- an unsigned string representation of the argument.
- Since:
- 1.8
- See Also:
 
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parseLongParses the string argument as a signedlongin the radix specified by the second argument. The characters in the string must all be digits of the specified radix (as determined by whetherCharacter.digit(char, int)returns a nonnegative value), except that the first character may be an ASCII minus sign'-'('\u002D') to indicate a negative value or an ASCII plus sign'+'('\u002B') to indicate a positive value. The resultinglongvalue is returned.Note that neither the character L('\u004C') norl('\u006C') is permitted to appear at the end of the string as a type indicator, as would be permitted in Java programming language source code - except that eitherLorlmay appear as a digit for a radix greater than or equal to 22.An exception of type NumberFormatExceptionis thrown if any of the following situations occurs:- The first argument is nullor is a string of length zero.
- The radixis either smaller thanCharacter.MIN_RADIXor larger thanCharacter.MAX_RADIX.
- Any character of the string is not a digit of the specified
 radix, except that the first character may be a minus sign
 '-'('\u002d') or plus sign'+'('\u002B') provided that the string is longer than length 1.
- The value represented by the string is not a value of type
      long.
 Examples: parseLong("0", 10) returns 0L parseLong("473", 10) returns 473L parseLong("+42", 10) returns 42L parseLong("-0", 10) returns 0L parseLong("-FF", 16) returns -255L parseLong("1100110", 2) returns 102L parseLong("99", 8) throws a NumberFormatException parseLong("Hazelnut", 10) throws a NumberFormatException parseLong("Hazelnut", 36) returns 1356099454469L- Parameters:
- s- the- Stringcontaining the- longrepresentation to be parsed.
- radix- the radix to be used while parsing- s.
- Returns:
- the longrepresented by the string argument in the specified radix.
- Throws:
- NumberFormatException- if the string does not contain a parsable- long.
 
- The first argument is 
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parseLongpublic static long parseLong(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException Parses theCharSequenceargument as a signedlongin the specifiedradix, beginning at the specifiedbeginIndexand extending toendIndex - 1.The method does not take steps to guard against the CharSequencebeing mutated while parsing.- Parameters:
- s- the- CharSequencecontaining the- longrepresentation to be parsed
- beginIndex- the beginning index, inclusive.
- endIndex- the ending index, exclusive.
- radix- the radix to be used while parsing- s.
- Returns:
- the signed longrepresented by the subsequence in the specified radix.
- Throws:
- NullPointerException- if- sis null.
- IndexOutOfBoundsException- if- beginIndexis negative, or if- beginIndexis greater than- endIndexor if- endIndexis greater than- s.length().
- NumberFormatException- if the- CharSequencedoes not contain a parsable- longin the specified- radix, or if- radixis either smaller than- Character.MIN_RADIXor larger than- Character.MAX_RADIX.
- Since:
- 9
 
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parseLongParses the string argument as a signed decimallong. The characters in the string must all be decimal digits, except that the first character may be an ASCII minus sign'-'(\u002D') to indicate a negative value or an ASCII plus sign'+'('\u002B') to indicate a positive value. The resultinglongvalue is returned, exactly as if the argument and the radix10were given as arguments to theparseLong(java.lang.String, int)method.Note that neither the character L('\u004C') norl('\u006C') is permitted to appear at the end of the string as a type indicator, as would be permitted in Java programming language source code.- Parameters:
- s- a- Stringcontaining the- longrepresentation to be parsed
- Returns:
- the longrepresented by the argument in decimal.
- Throws:
- NumberFormatException- if the string does not contain a parsable- long.
 
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parseUnsignedLongParses the string argument as an unsignedlongin the radix specified by the second argument. An unsigned integer maps the values usually associated with negative numbers to positive numbers larger thanMAX_VALUE. The characters in the string must all be digits of the specified radix (as determined by whetherCharacter.digit(char, int)returns a nonnegative value), except that the first character may be an ASCII plus sign'+'('\u002B'). The resulting integer value is returned.An exception of type NumberFormatExceptionis thrown if any of the following situations occurs:- The first argument is nullor is a string of length zero.
- The radix is either smaller than
 Character.MIN_RADIXor larger thanCharacter.MAX_RADIX.
- Any character of the string is not a digit of the specified
 radix, except that the first character may be a plus sign
 '+'('\u002B') provided that the string is longer than length 1.
- The value represented by the string is larger than the
 largest unsigned long, 264-1.
 - Parameters:
- s- the- Stringcontaining the unsigned integer representation to be parsed
- radix- the radix to be used while parsing- s.
- Returns:
- the unsigned longrepresented by the string argument in the specified radix.
- Throws:
- NumberFormatException- if the- Stringdoes not contain a parsable- long.
- Since:
- 1.8
 
- The first argument is 
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parseUnsignedLongpublic static long parseUnsignedLong(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException Parses theCharSequenceargument as an unsignedlongin the specifiedradix, beginning at the specifiedbeginIndexand extending toendIndex - 1.The method does not take steps to guard against the CharSequencebeing mutated while parsing.- Parameters:
- s- the- CharSequencecontaining the unsigned- longrepresentation to be parsed
- beginIndex- the beginning index, inclusive.
- endIndex- the ending index, exclusive.
- radix- the radix to be used while parsing- s.
- Returns:
- the unsigned longrepresented by the subsequence in the specified radix.
- Throws:
- NullPointerException- if- sis null.
- IndexOutOfBoundsException- if- beginIndexis negative, or if- beginIndexis greater than- endIndexor if- endIndexis greater than- s.length().
- NumberFormatException- if the- CharSequencedoes not contain a parsable unsigned- longin the specified- radix, or if- radixis either smaller than- Character.MIN_RADIXor larger than- Character.MAX_RADIX.
- Since:
- 9
 
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parseUnsignedLongParses the string argument as an unsigned decimallong. The characters in the string must all be decimal digits, except that the first character may be an ASCII plus sign'+'('\u002B'). The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to theparseUnsignedLong(java.lang.String, int)method.- Parameters:
- s- a- Stringcontaining the unsigned- longrepresentation to be parsed
- Returns:
- the unsigned longvalue represented by the decimal string argument
- Throws:
- NumberFormatException- if the string does not contain a parsable unsigned integer.
- Since:
- 1.8
 
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valueOfReturns aLongobject holding the value extracted from the specifiedStringwhen parsed with the radix given by the second argument. The first argument is interpreted as representing a signedlongin the radix specified by the second argument, exactly as if the arguments were given to theparseLong(java.lang.String, int)method. The result is aLongobject that represents thelongvalue specified by the string.In other words, this method returns a Longobject equal to the value of:new Long(Long.parseLong(s, radix))- Parameters:
- s- the string to be parsed
- radix- the radix to be used in interpreting- s
- Returns:
- a Longobject holding the value represented by the string argument in the specified radix.
- Throws:
- NumberFormatException- If the- Stringdoes not contain a parsable- long.
 
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valueOfReturns aLongobject holding the value of the specifiedString. The argument is interpreted as representing a signed decimallong, exactly as if the argument were given to theparseLong(java.lang.String)method. The result is aLongobject that represents the integer value specified by the string.In other words, this method returns a Longobject equal to the value of:new Long(Long.parseLong(s))- Parameters:
- s- the string to be parsed.
- Returns:
- a Longobject holding the value represented by the string argument.
- Throws:
- NumberFormatException- If the string cannot be parsed as a- long.
 
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valueOfReturns aLonginstance representing the specifiedlongvalue. If a newLonginstance is not required, this method should generally be used in preference to the constructorLong(long), as this method is likely to yield significantly better space and time performance by caching frequently requested values. This method will always cache values in the range -128 to 127, inclusive, and may cache other values outside of this range.- Parameters:
- l- a long value.
- Returns:
- a Longinstance representingl.
- Since:
- 1.5
 
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decodeDecodes aStringinto aLong. Accepts decimal, hexadecimal, and octal numbers given by the following grammar:
 DecimalNumeral, HexDigits, and OctalDigits are as defined in section 3.10.1 of The Java Language Specification, except that underscores are not accepted between digits.- DecodableString:
- Signopt DecimalNumeral
 - Signopt
0xHexDigits
- Signopt
0XHexDigits
- Signopt
#HexDigits
- Signopt
0OctalDigits
- Signopt
- Sign:
- -- +
 The sequence of characters following an optional sign and/or radix specifier (" 0x", "0X", "#", or leading zero) is parsed as by theLong.parseLongmethod with the indicated radix (10, 16, or 8). This sequence of characters must represent a positive value or aNumberFormatExceptionwill be thrown. The result is negated if first character of the specifiedStringis the minus sign. No whitespace characters are permitted in theString.- Parameters:
- nm- the- Stringto decode.
- Returns:
- a Longobject holding thelongvalue represented bynm
- Throws:
- NumberFormatException- if the- Stringdoes not contain a parsable- long.
- Since:
- 1.2
- See Also:
 
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byteValuepublic byte byteValue()Returns the value of thisLongas abyteafter a narrowing primitive conversion.- Overrides:
- byteValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type byte.
- See Java Language Specification:
- 
5.1.3 Narrowing Primitive Conversion
 
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shortValuepublic short shortValue()Returns the value of thisLongas ashortafter a narrowing primitive conversion.- Overrides:
- shortValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type short.
- See Java Language Specification:
- 
5.1.3 Narrowing Primitive Conversion
 
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intValuepublic int intValue()Returns the value of thisLongas anintafter a narrowing primitive conversion.- Specified by:
- intValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type int.
- See Java Language Specification:
- 
5.1.3 Narrowing Primitive Conversion
 
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longValuepublic long longValue()Returns the value of thisLongas alongvalue.
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floatValuepublic float floatValue()Returns the value of thisLongas afloatafter a widening primitive conversion.- Specified by:
- floatValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type float.
- See Java Language Specification:
- 
5.1.2 Widening Primitive Conversion
 
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doubleValuepublic double doubleValue()Returns the value of thisLongas adoubleafter a widening primitive conversion.- Specified by:
- doubleValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type double.
- See Java Language Specification:
- 
5.1.2 Widening Primitive Conversion
 
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toStringReturns aStringobject representing thisLong's value. The value is converted to signed decimal representation and returned as a string, exactly as if thelongvalue were given as an argument to thetoString(long)method.
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hashCodepublic int hashCode()Returns a hash code for thisLong. The result is the exclusive OR of the two halves of the primitivelongvalue held by thisLongobject. That is, the hashcode is the value of the expression:(int)(this.longValue()^(this.longValue()>>>32))
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hashCodepublic static int hashCode(long value) Returns a hash code for alongvalue; compatible withLong.hashCode().- Parameters:
- value- the value to hash
- Returns:
- a hash code value for a longvalue.
- Since:
- 1.8
 
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equalsCompares this object to the specified object. The result istrueif and only if the argument is notnulland is aLongobject that contains the samelongvalue as this object.
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getLongDetermines thelongvalue of the system property with the specified name.The first argument is treated as the name of a system property. System properties are accessible through the System.getProperty(java.lang.String)method. The string value of this property is then interpreted as alongvalue using the grammar supported bydecodeand aLongobject representing this value is returned.If there is no property with the specified name, if the specified name is empty or null, or if the property does not have the correct numeric format, thennullis returned.In other words, this method returns a Longobject equal to the value of:getLong(nm, null)- Parameters:
- nm- property name.
- Returns:
- the Longvalue of the property.
- Throws:
- SecurityException- for the same reasons as- System.getProperty
- See Also:
 
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getLongDetermines thelongvalue of the system property with the specified name.The first argument is treated as the name of a system property. System properties are accessible through the System.getProperty(java.lang.String)method. The string value of this property is then interpreted as alongvalue using the grammar supported bydecodeand aLongobject representing this value is returned.The second argument is the default value. A Longobject that represents the value of the second argument is returned if there is no property of the specified name, if the property does not have the correct numeric format, or if the specified name is empty or null.In other words, this method returns a Longobject equal to the value of:
 but in practice it may be implemented in a manner such as:getLong(nm, new Long(val))
 to avoid the unnecessary allocation of aLong result = getLong(nm, null); return (result == null) ? new Long(val) : result; Longobject when the default value is not needed.- Parameters:
- nm- property name.
- val- default value.
- Returns:
- the Longvalue of the property.
- Throws:
- SecurityException- for the same reasons as- System.getProperty
- See Also:
 
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getLongReturns thelongvalue of the system property with the specified name. The first argument is treated as the name of a system property. System properties are accessible through theSystem.getProperty(java.lang.String)method. The string value of this property is then interpreted as alongvalue, as per thedecodemethod, and aLongobject representing this value is returned; in summary:- If the property value begins with the two ASCII characters
 0xor the ASCII character#, not followed by a minus sign, then the rest of it is parsed as a hexadecimal integer exactly as for the methodvalueOf(java.lang.String, int)with radix 16.
- If the property value begins with the ASCII character
 0followed by another character, it is parsed as an octal integer exactly as by the methodvalueOf(java.lang.String, int)with radix 8.
- Otherwise the property value is parsed as a decimal
 integer exactly as by the method
 valueOf(java.lang.String, int)with radix 10.
 Note that, in every case, neither L('\u004C') norl('\u006C') is permitted to appear at the end of the property value as a type indicator, as would be permitted in Java programming language source code.The second argument is the default value. The default value is returned if there is no property of the specified name, if the property does not have the correct numeric format, or if the specified name is empty or null.- Parameters:
- nm- property name.
- val- default value.
- Returns:
- the Longvalue of the property.
- Throws:
- SecurityException- for the same reasons as- System.getProperty
- See Also:
 
- If the property value begins with the two ASCII characters
 
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compareToCompares twoLongobjects numerically.- Specified by:
- compareToin interface- Comparable<Long>
- Parameters:
- anotherLong- the- Longto be compared.
- Returns:
- the value 0if thisLongis equal to the argumentLong; a value less than0if thisLongis numerically less than the argumentLong; and a value greater than0if thisLongis numerically greater than the argumentLong(signed comparison).
- Since:
- 1.2
 
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comparepublic static int compare(long x, long y) Compares twolongvalues numerically. The value returned is identical to what would be returned by:Long.valueOf(x).compareTo(Long.valueOf(y))- Parameters:
- x- the first- longto compare
- y- the second- longto compare
- Returns:
- the value 0ifx == y; a value less than0ifx < y; and a value greater than0ifx > y
- Since:
- 1.7
 
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compareUnsignedpublic static int compareUnsigned(long x, long y) Compares twolongvalues numerically treating the values as unsigned.- Parameters:
- x- the first- longto compare
- y- the second- longto compare
- Returns:
- the value 0ifx == y; a value less than0ifx < yas unsigned values; and a value greater than0ifx > yas unsigned values
- Since:
- 1.8
 
- 
divideUnsignedpublic static long divideUnsigned(long dividend, long divisor) Returns the unsigned quotient of dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.Note that in two's complement arithmetic, the three other basic arithmetic operations of add, subtract, and multiply are bit-wise identical if the two operands are regarded as both being signed or both being unsigned. Therefore separate addUnsigned, etc. methods are not provided.- Parameters:
- dividend- the value to be divided
- divisor- the value doing the dividing
- Returns:
- the unsigned quotient of the first argument divided by the second argument
- Since:
- 1.8
- See Also:
 
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remainderUnsignedpublic static long remainderUnsigned(long dividend, long divisor) Returns the unsigned remainder from dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.- Parameters:
- dividend- the value to be divided
- divisor- the value doing the dividing
- Returns:
- the unsigned remainder of the first argument divided by the second argument
- Since:
- 1.8
- See Also:
 
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highestOneBitpublic static long highestOneBit(long i) Returns alongvalue with at most a single one-bit, in the position of the highest-order ("leftmost") one-bit in the specifiedlongvalue. Returns zero if the specified value has no one-bits in its two's complement binary representation, that is, if it is equal to zero.- Parameters:
- i- the value whose highest one bit is to be computed
- Returns:
- a longvalue with a single one-bit, in the position of the highest-order one-bit in the specified value, or zero if the specified value is itself equal to zero.
- Since:
- 1.5
 
- 
lowestOneBitpublic static long lowestOneBit(long i) Returns alongvalue with at most a single one-bit, in the position of the lowest-order ("rightmost") one-bit in the specifiedlongvalue. Returns zero if the specified value has no one-bits in its two's complement binary representation, that is, if it is equal to zero.- Parameters:
- i- the value whose lowest one bit is to be computed
- Returns:
- a longvalue with a single one-bit, in the position of the lowest-order one-bit in the specified value, or zero if the specified value is itself equal to zero.
- Since:
- 1.5
 
- 
numberOfLeadingZerospublic static int numberOfLeadingZeros(long i) Returns the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specifiedlongvalue. Returns 64 if the specified value has no one-bits in its two's complement representation, in other words if it is equal to zero.Note that this method is closely related to the logarithm base 2. For all positive longvalues x:- floor(log2(x)) = 63 - numberOfLeadingZeros(x)
- ceil(log2(x)) = 64 - numberOfLeadingZeros(x - 1)
 - Parameters:
- i- the value whose number of leading zeros is to be computed
- Returns:
- the number of zero bits preceding the highest-order
     ("leftmost") one-bit in the two's complement binary representation
     of the specified longvalue, or 64 if the value is equal to zero.
- Since:
- 1.5
 
- floor(log2(x)) = 
- 
numberOfTrailingZerospublic static int numberOfTrailingZeros(long i) Returns the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specifiedlongvalue. Returns 64 if the specified value has no one-bits in its two's complement representation, in other words if it is equal to zero.- Parameters:
- i- the value whose number of trailing zeros is to be computed
- Returns:
- the number of zero bits following the lowest-order ("rightmost")
     one-bit in the two's complement binary representation of the
     specified longvalue, or 64 if the value is equal to zero.
- Since:
- 1.5
 
- 
bitCountpublic static int bitCount(long i) Returns the number of one-bits in the two's complement binary representation of the specifiedlongvalue. This function is sometimes referred to as the population count.- Parameters:
- i- the value whose bits are to be counted
- Returns:
- the number of one-bits in the two's complement binary
     representation of the specified longvalue.
- Since:
- 1.5
 
- 
rotateLeftpublic static long rotateLeft(long i, int distance) Returns the value obtained by rotating the two's complement binary representation of the specifiedlongvalue left by the specified number of bits. (Bits shifted out of the left hand, or high-order, side reenter on the right, or low-order.)Note that left rotation with a negative distance is equivalent to right rotation: rotateLeft(val, -distance) == rotateRight(val, distance). Note also that rotation by any multiple of 64 is a no-op, so all but the last six bits of the rotation distance can be ignored, even if the distance is negative:rotateLeft(val, distance) == rotateLeft(val, distance & 0x3F).- Parameters:
- i- the value whose bits are to be rotated left
- distance- the number of bit positions to rotate left
- Returns:
- the value obtained by rotating the two's complement binary
     representation of the specified longvalue left by the specified number of bits.
- Since:
- 1.5
 
- 
rotateRightpublic static long rotateRight(long i, int distance) Returns the value obtained by rotating the two's complement binary representation of the specifiedlongvalue right by the specified number of bits. (Bits shifted out of the right hand, or low-order, side reenter on the left, or high-order.)Note that right rotation with a negative distance is equivalent to left rotation: rotateRight(val, -distance) == rotateLeft(val, distance). Note also that rotation by any multiple of 64 is a no-op, so all but the last six bits of the rotation distance can be ignored, even if the distance is negative:rotateRight(val, distance) == rotateRight(val, distance & 0x3F).- Parameters:
- i- the value whose bits are to be rotated right
- distance- the number of bit positions to rotate right
- Returns:
- the value obtained by rotating the two's complement binary
     representation of the specified longvalue right by the specified number of bits.
- Since:
- 1.5
 
- 
reversepublic static long reverse(long i) Returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specifiedlongvalue.- Parameters:
- i- the value to be reversed
- Returns:
- the value obtained by reversing order of the bits in the
     specified longvalue.
- Since:
- 1.5
 
- 
signumpublic static int signum(long i) Returns the signum function of the specifiedlongvalue. (The return value is -1 if the specified value is negative; 0 if the specified value is zero; and 1 if the specified value is positive.)- Parameters:
- i- the value whose signum is to be computed
- Returns:
- the signum function of the specified longvalue.
- Since:
- 1.5
 
- 
reverseBytespublic static long reverseBytes(long i) Returns the value obtained by reversing the order of the bytes in the two's complement representation of the specifiedlongvalue.- Parameters:
- i- the value whose bytes are to be reversed
- Returns:
- the value obtained by reversing the bytes in the specified
     longvalue.
- Since:
- 1.5
 
- 
sumpublic static long sum(long a, long b) Adds twolongvalues together as per the + operator.- Parameters:
- a- the first operand
- b- the second operand
- Returns:
- the sum of aandb
- Since:
- 1.8
- See Also:
 
- 
maxpublic static long max(long a, long b) Returns the greater of twolongvalues as if by callingMath.max.- Parameters:
- a- the first operand
- b- the second operand
- Returns:
- the greater of aandb
- Since:
- 1.8
- See Also:
 
- 
minpublic static long min(long a, long b) Returns the smaller of twolongvalues as if by callingMath.min.- Parameters:
- a- the first operand
- b- the second operand
- Returns:
- the smaller of aandb
- Since:
- 1.8
- See Also:
 
- 
describeConstableReturns anOptionalcontaining the nominal descriptor for this instance, which is the instance itself.- Specified by:
- describeConstablein interface- Constable
- Returns:
- an Optionaldescribing the Long instance
- Since:
- 12
 
- 
resolveConstantDescResolves this instance as aConstantDesc, the result of which is the instance itself.- Specified by:
- resolveConstantDescin interface- ConstantDesc
- Parameters:
- lookup- ignored
- Returns:
- the Long instance
- Since:
- 12
 
 
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