Javascript Array polyfills

gistfile1.txt

Array.prototype.remove = function(from, to) {
    var rest = this.slice((to || from) + 1 || this.length);
    this.length = from < 0 ? this.length + from : from;
    return this.push.apply(this, rest);
};

if (!Array.prototype.indexOf){
    Array.prototype.indexOf = function(elt /*, from*/)
    {
        var len = this.length >>> 0;
        var from = Number(arguments[1]) || 0;
        from = (from < 0)
            ? Math.ceil(from)
            : Math.floor(from);
        if (from < 0)
            from += len;

        for (; from < len; from++)
        {
            if (from in this &&
                this[from] === elt)
                return from;
        }
        return -1;
    };
}


if (!Array.prototype.map){
    Array.prototype.map = function(fun /*, thisArg */)
    {
        "use strict";

        if (this === void 0 || this === null)
            throw new TypeError();

        var t = Object(this);
        var len = t.length >>> 0;
        if (typeof fun !== "function")
            throw new TypeError();

        var res = new Array(len);
        var thisArg = arguments.length >= 2 ? arguments[1] : void 0;
        for (var i = 0; i < len; i++)
        {
            // NOTE: Absolute correctness would demand Object.defineProperty
            //       be used.  But this method is fairly new, and failure is
            //       possible only if Object.prototype or Array.prototype
            //       has a property |i| (very unlikely), so use a less-correct
            //       but more portable alternative.
            if (i in t)
                res[i] = fun.call(thisArg, t[i], i, t);
        }

        return res;
    };
}