我是歌谣 放弃很容易 但坚持一定很酷
公众号小歌谣 谢谢关注

前言

Foreach

Array.prototype.myForEach = function (cb) {var _arr = this;var _len = _arr.length;var _arg2 = arguments[1] || window;for (var i = 0; i < _len; i ++) {cb.apply(_arg2, [_arr[i], i, _arr]);}
}

Map

Array.prototype.myMap  = function (cb) {var _arr = this;var _len = _arr.length;var _arg2 = arguments[1] || window;var _newArr = [];var _item;var _res;for (var i = 0; i < _len; i ++) {_item = deepClone(_arr[i]);_res = cb.apply(_arg2, [_item, i, _arr]);_res && _newArr.push(_res);}return _newArr;
}

Filter

Array.prototype.myFilter = function (cb) {var _arr = this;var _len = _arr.length;var _arg2 = arguments[1] || window;var _newArr = [];var _item;for (var i = 0; i < _len; i ++) {_item = deepClone(_arr[i]);cb.apply(_arg2, [_item, i, _arr]) ? _newArr.push(_item) : '';}return _newArr;
}

Every

Array.prototype.myEvery = function (cb) {var _arr = this;var _len = _arr.length;var arg2 = arguments[1] || window;var _res = true;for (var i = 0; i < _len; i ++) {if (!cb.apply(arg2, [_arr[i], i, _arr])) {_res = false;break;}}return _res;
}

Some

Array.prototype.mySome = function (cb) {var _arr = this;var _len = _arr.length;var _arg2 = arguments[1] || window;var _res = false;for (var i = 0; i < _len; i ++) {if (cb.apply(_arg2, [_arr[i], i, _arr])) {_res = true;break;}}return _res;
}

Reduce

function deepClone (origin, target) {var tar = target || {};var toStr = Object.prototype.toString;var arrayType = '[object Array]';for (var k in origin) {if (origin.hasOwnProperty(k)) {if (typeof origin[k] === 'object' && origin[k] !== null) {tar[k] = toStr.call(origin[k]) === arrayType ? [] : {};deepClone(origin[k], tar[k]);} else {tar[k] = origin[k];}}}return tar;
}

Array.prototype.myReduce = function (cb, initialValue) {var _arr = this;var _len = _arr.length;var _arg3 = arguments[2] || window;var _item;for (var i = 0; i < _len; i ++) {_item = deepClone(_arr[i]);initialValue = cb.apply(_arg3, [initialValue, _item, i, _arr]);}return initialValue;
}

reduceRight

Array.prototype.myReduceRight = function (cb, initialValue) {var _arr = this;var _len = _arr.length;var _arg3 = arguments[2] || window;var _item;for (var i = _len; i >= 0; i --) {_item = deepClone(_arr[i]);initialValue = cb.apply(_arg3, [initialValue, _item, i, _arr]);}return initialValue;
}

我是歌谣放弃很难 但是坚持一定很酷