mdnJavaScript.js

/*
Array generic methods
These are currently not part of ECMAScript standards (though the ES6 Array.from() can be used to achieve this).
The following is a shim to allow its use in all browsers:
src: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
*/

(function () {
    'use strict';

    var i,
        // We could also build the array of methods with the following, but the
        //   getOwnPropertyNames() method is non-shimable:
        // Object.getOwnPropertyNames(Array).filter(function (methodName) {
        //     return typeof Array[methodName] === 'function'});
        methods = [
            'join', 'reverse', 'sort', 'push', 'pop', 'shift', 'unshift',
            'splice', 'concat', 'slice', 'indexOf', 'lastIndexOf',
            'forEach', 'map', 'reduce', 'reduceRight', 'filter',
            'some', 'every'
        ],
        methodCount = methods.length,
        assignArrayGeneric = function (methodName) {
            if (!Array[methodName]) {
                var method = Array.prototype[methodName];
                if (typeof method === 'function') {
                    Array[methodName] = function () {
                        return method.call.apply(method, arguments);
                    };
                }
            }
        };

    for (i = 0; i < methodCount; i++) {
        assignArrayGeneric(methods[i]);
    }
}());