raptor-polyfill/array/filter.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 15.4.4.20
// http://es5.github.com/#x15.4.4.20
// https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Objects/Array/filter
if (!Array.prototype.filter) {
    var toObject = require('./_toObject');
    
    Array.prototype.filter = function filter(fun /*, thisp */) {
        var self = toObject(this),
            length = self.length >>> 0,
            result = [],
            value,
            thisp = arguments[1];

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

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