raptor-polyfill/array/map.js

Polyfills for various EcmaScript 5 and EcmaScript 6 methods distributed as CommonJS modules that can be require'd individually or as a whole.

// ES5 15.4.4.19
// http://es5.github.com/#x15.4.4.19
// https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Objects/Array/map
if (!Array.prototype.map) {
    var toObject = require('./_toObject');

    Array.prototype.map = function map(fun /*, thisp*/) {
        var self = toObject(this),
            length = self.length >>> 0,
            result = new Array(length),
            thisp = arguments[1];

        // If no callback function or if callback is not a callable function
        if (typeof fun !== 'function') {
            throw new TypeError(fun + " is not a function");
        }

        for (var i = 0; i < length; i++) {
            if (i in self)
                result[i] = fun.call(thisp, self[i], i, self);
        }
        return result;
    };
}