Math.random()

gistfile1.js

/*
It has always bugged me that every other language except Java returns an integer and JavaScript returns [0,1).
So, how about standarizing this?
*/
(function () {
    var oldRandom = Math.random;

    Object.defineProperty(Math, 'random', {
        value: function random(n) {
            return typeof n === 'undefined' ? oldRandom() : 
            	   typeof n === 'number' && Math.abs(n) <= Number.MAX_INTEGER ? Math.floor(oldRandom() * Math.floor(n)) : 
            	   NaN;
        },
        configurable: true,
        writable: true
    });
}());

// Or at least...

Object.defineProperty(Math, 'randomInt', {
    value: function randomInt(n) {
        if (typeof n === 'undefined') {
            n = Number.MAX_INTEGER;
        }
        return typeof n === 'number' && Math.abs(n) <= Number.MAX_INTEGER ? Math.floor(Math.random() * Math.floor(n)) : NaN;
    },
    configurable: true,
    writable: true
});

// Another proposal from @joseanpg Twitter

(function () {
	
    function isNumberInIntRange(n) { return typeof n === 'number' && Math.abs(n) <= Number.MAX_INTEGER }

    Object.defineProperty(Math, 'randomInt', {
        value: function randomInt(a, b) {
            if (typeof b === 'undefined') {
                b = typeof a === 'undefined' ? Number.MAX_INTEGER : a;
                a = 0;
            } else if (typeof a === 'undefined') {
                a = 0;
            }
            return isNumberInIntRange(a) && isNumberInIntRange(b) ? Math.floor(Math.random() * Math.floor(b)) + a : NaN;
        },
        configurable: true,
        writable: true
    });

}());