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long.js - A Long class for representing a 64 bit two's-complement integer

A Long class for representing a 64 bit two's-complement integer value derived from the Closure Library for stand-alone use and extended with unsigned support.

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Background

As of ECMA-262 5th Edition, "all the positive and negative integers whose magnitude is no greater than 253 are representable in the Number type", which is "representing the doubleprecision 64-bit format IEEE 754 values as specified in the IEEE Standard for Binary Floating-Point Arithmetic". The maximum safe integer in JavaScript is 253-1.

Example: 264-1 is 18446744073709551615 but in JavaScript it evaluates to 18446744073709552000.

Furthermore, bitwise operators in JavaScript "deal only with integers in the range −231 through 231−1, inclusive, or in the range 0 through 232−1, inclusive. These operators accept any value of the Number type but first convert each such value to one of 232 integer values."

In some use cases, however, it is required to be able to reliably work with and perform bitwise operations on the full 64 bits. This is where long.js comes into play.

Usage

The class is compatible with CommonJS and AMD loaders and is exposed globally as dcodeIO.Long if neither is available.

var Long = require("long");
 
var longVal = new Long(0xFFFFFFFF, 0x7FFFFFFF);
console.log(longVal.toString());
...

API

new Long(low, high=, unsigned=)

Constructs a 64 bit two's-complement integer, given its low and high 32 bit values as signed integers. See the from* functions below for more convenient ways of constructing Longs.

Parameter Type Description
low number The low (signed) 32 bits of the long
high number The high (signed) 32 bits of the long
unsigned boolean Whether unsigned or not, defaults to false for signed

Long.MAX_UNSIGNED_VALUE

Maximum unsigned value.

@type !Long

Long.MAX_VALUE

Maximum signed value.

@type !Long

Long.MIN_VALUE

Minimum signed value.

@type !Long

Long.NEG_ONE

Signed negative one.

@type !Long

Long.ONE

Signed one.

@type !Long

Long.UONE

Unsigned one.

@type !Long

Long.UZERO

Unsigned zero.

@type !Long

Long.ZERO

Signed zero.

@type !Long

Long.fromBits(lowBits, highBits, unsigned=)

Returns a Long representing the 64 bit integer that comes by concatenating the given low and high bits. Each is assumed to use 32 bits.

Parameter Type Description
lowBits number The low 32 bits
highBits number The high 32 bits
unsigned boolean Whether unsigned or not, defaults to false for signed
@returns !Long The corresponding Long value

Long.fromInt(value, unsigned=)

Returns a Long representing the given 32 bit integer value.

Parameter Type Description
value number The 32 bit integer in question
unsigned boolean Whether unsigned or not, defaults to false for signed
@returns !Long The corresponding Long value

Long.fromNumber(value, unsigned=)

Returns a Long representing the given value, provided that it is a finite number. Otherwise, zero is returned.

Parameter Type Description
value number The number in question
unsigned boolean Whether unsigned or not, defaults to false for signed
@returns !Long The corresponding Long value

Long.fromString(str, unsigned=, radix=)

Returns a Long representation of the given string, written using the specified radix.

Parameter Type Description
str string The textual representation of the Long
unsigned boolean | number Whether unsigned or not, defaults to false for signed
radix number The radix in which the text is written (2-36), defaults to 10
@returns !Long The corresponding Long value

Long.isLong(obj)

Tests if the specified object is a Long.

Parameter Type Description
obj *** Object
@returns boolean

Long.fromValue(val)

Converts the specified value to a Long.

Parameter Type Description
val !Long | number | string | !{low: number, high: number, unsigned: boolean} Value
@returns !Long

Long#high

The high 32 bits as a signed value.

@type number

Long#low

The low 32 bits as a signed value.

@type number

Long#unsigned

Whether unsigned or not.

@type boolean

Long#add(addend)

Returns the sum of this and the specified Long.

Parameter Type Description
addend !Long | number | string Addend
@returns !Long Sum

Long#and(other)

Returns the bitwise AND of this Long and the specified.

Parameter Type Description
other !Long | number | string Other Long
@returns !Long

Long#compare/comp(other)

Compares this Long's value with the specified's.

Parameter Type Description
other !Long | number | string Other value
@returns number 0 if they are the same, 1 if the this is greater and -1 if the given one is greater

Long#divide/div(divisor)

Returns this Long divided by the specified.

Parameter Type Description
divisor !Long | number | string Divisor
@returns !Long Quotient

Long#equals/eq(other)

Tests if this Long's value equals the specified's.

Parameter Type Description
other !Long | number | string Other value
@returns boolean

Long#getHighBits()

Gets the high 32 bits as a signed integer.

Parameter Type Description
@returns number Signed high bits

Long#getHighBitsUnsigned()

Gets the high 32 bits as an unsigned integer.

Parameter Type Description
@returns number Unsigned high bits

Long#getLowBits()

Gets the low 32 bits as a signed integer.

Parameter Type Description
@returns number Signed low bits

Long#getLowBitsUnsigned()

Gets the low 32 bits as an unsigned integer.

Parameter Type Description
@returns number Unsigned low bits

Long#getNumBitsAbs()

Gets the number of bits needed to represent the absolute value of this Long.

Parameter Type Description
@returns number

Long#greaterThan/gt(other)

Tests if this Long's value is greater than the specified's.

Parameter Type Description
other !Long | number | string Other value
@returns boolean

Long#greaterThanOrEqual/gte(other)

Tests if this Long's value is greater than or equal the specified's.

Parameter Type Description
other !Long | number | string Other value
@returns boolean

Long#isEven()

Tests if this Long's value is even.

Parameter Type Description
@returns boolean

Long#isNegative()

Tests if this Long's value is negative.

Parameter Type Description
@returns boolean

Long#isOdd()

Tests if this Long's value is odd.

Parameter Type Description
@returns boolean

Long#isPositive()

Tests if this Long's value is positive.

Parameter Type Description
@returns boolean

Long#isZero()

Tests if this Long's value equals zero.

Parameter Type Description
@returns boolean

Long#lessThan/lt(other)

Tests if this Long's value is less than the specified's.

Parameter Type Description
other !Long | number | string Other value
@returns boolean

Long#lessThanOrEqual/lte(other)

Tests if this Long's value is less than or equal the specified's.

Parameter Type Description
other !Long | number | string Other value
@returns boolean

Long#modulo/mod(divisor)

Returns this Long modulo the specified.

Parameter Type Description
divisor !Long | number | string Divisor
@returns !Long Remainder

Long#multiply/mul(multiplier)

Returns the product of this and the specified Long.

Parameter Type Description
multiplier !Long | number | string Multiplier
@returns !Long Product

Long#negate/neg()

Negates this Long's value.

Parameter Type Description
@returns !Long Negated Long

Long#not()

Returns the bitwise NOT of this Long.

Parameter Type Description
@returns !Long

Long#notEquals/neq(other)

Tests if this Long's value differs from the specified's.

Parameter Type Description
other !Long | number | string Other value
@returns boolean

Long#or(other)

Returns the bitwise OR of this Long and the specified.

Parameter Type Description
other !Long | number | string Other Long
@returns !Long

Long#shiftLeft/shl(numBits)

Returns this Long with bits shifted to the left by the given amount.

Parameter Type Description
numBits number | !Long Number of bits
@returns !Long Shifted Long

Long#shiftRight/shr(numBits)

Returns this Long with bits arithmetically shifted to the right by the given amount.

Parameter Type Description
numBits number | !Long Number of bits
@returns !Long Shifted Long

Long#shiftRightUnsigned/shru(numBits)

Returns this Long with bits logically shifted to the right by the given amount.

Parameter Type Description
numBits number | !Long Number of bits
@returns !Long Shifted Long

Long#subtract/sub(subtrahend)

Returns the difference of this and the specified Long.

Parameter Type Description
subtrahend !Long | number | string Subtrahend
@returns !Long Difference

Long#toInt()

Converts the Long to a 32 bit integer, assuming it is a 32 bit integer.

Parameter Type Description
@returns number

Long#toNumber()

Converts the Long to a the nearest floating-point representation of this value (double, 53 bit mantissa).

Parameter Type Description
@returns number

Long#toSigned()

Converts this Long to signed.

Parameter Type Description
@returns !Long Signed long

Long#toString(radix=)

Converts the Long to a string written in the specified radix.

Parameter Type Description
radix number Radix (2-36), defaults to 10
@returns string
@throws RangeError If radix is out of range

Long#toUnsigned()

Converts this Long to unsigned.

Parameter Type Description
@returns !Long Unsigned long

Long#xor(other)

Returns the bitwise XOR of this Long and the given one.

Parameter Type Description
other !Long | number | string Other Long
@returns !Long

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License

Apache License, Version 2.0 - http://www.apache.org/licenses/LICENSE-2.0.html