Long.js

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.

Why?

As of the ECMAScript specification, number types have a maximum value of 2^53. Beyond that, behaviour might be unexpected. Furthermore, bitwise operations are always performed on 32bit numbers. However, in some use cases it is required to be able to perform reliable mathematical and/or bitwise operations on the full 64bits. This is where Long.js comes into play.

Long.js is based on the goog.math.Long class from the Closure Library. It uses two 32bit integers internally and provides methods for comparison, common tests, math and bitwise operations on the full 64bits. Additionally, some use cases also require to work with 64bit unsigned values, so Long.js has been extended with unsigned support while maintaining compatibility to the Closure Library implementation.

Features

CommonJS compatible
RequireJS/AMD compatible
Shim compatible (include the script, then use var Long = dcodeIO.Long;)
node.js compatible, also available via npm
Fully documented using jsdoc3
Zero production dependencies
Small footprint

Long

Construction from high and low bits as 32bit integers: new Long(low, high[, unsigned=false]) and Long.fromBits(low, high[, unsigned=false])
...from a 32bit integer: Long.fromInt(value[, unsigned=false]) including a cache for frequently used small numbers
...from a number which may internally be a number or double type: Long.fromNumber(value[, unsigned=false])
...from a string: Long.fromString(value[, unsigned=false, radix=10])
Conversion to a 32bit integer: Long#toInt()
...to a number: Long#toNumber()
...to a string: Long#toString([radix=10])
Getters for high and low bits as 32bit integers: Long#getLowBits(), Long#getHighBits() and Long#getLowBitsUnsigned(), Long#getHighBitsUnsigned()
Comparison: Long#equals(other), Long#notEquals(other), Long#lessThan(other), Long#lessThanOrEqual(other), Long#greaterThan(other), Long#greaterThanOrEqual(other), Long#compare(other)
Common tests: Long#isZero(), Long#isNegative(), Long#isOdd(), Long#isEven()
Math: Long#negate(), Long#add(other), Long#subtract(other), Long#multiply(other), Long#div(other), Long#modulo(other)
Bitwise operations: Long#not(), Long#and(other), Long#or(other), Long#xor(other), Long#shiftLeft(numBits), Long#shiftRight(numBits), Long#shiftRightUnsigned(numBits)
Conversion between signed and unsinged: Long.toSigned(), Long.toUnsigned()

Usage

node.js / CommonJS

Install: npm install long

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

RequireJS / AMD

require.config({
    "paths": {
        "Math/Long": "/path/to/Long.js"
    }
});
require(["Math/Long"], function(Long) {
    var longVal = new Long(0xFFFFFFFF, 0x7FFFFFFF);
    console.log(longVal.toString());
});

Browser / shim

<script src="//raw.github.com/dcodeIO/Long.js/master/Long.min.js"></script>

var Long = dcodeIO.Long;
var longVal = new Long(0xFFFFFFFF, 0x7FFFFFFF);
alert(longVal.toString());

guancio/Long.js