Array.prototype.forEach = function (action) {
for (var i = 0; i < this.length; i++) {
action(this[i]);
}
};
/**
* 以jqery 对象的方式迭代对象
* @param {} action
* @returns {}
*/
Array.prototype.forEachJq = function (action) {
for (var i = 0; i < this.length; i++) {
action($(this[i]));
}
};

-----------------------------------------------------------------

// Production steps of ECMA-262, Edition 5, 15.4.4.18// Reference: http://es5.github.io/#x15.4.4.18if (!Array.prototype.forEach) {  Array.prototype.forEach = function(callback, thisArg) {    var T, k;    if (this == null) {      throw new TypeError(‘ this is null or not defined‘);    }    // 1. Let O be the result of calling toObject() passing the    // |this| value as the argument.    var O = Object(this);    // 2. Let lenValue be the result of calling the Get() internal    // method of O with the argument "length".    // 3. Let len be toUint32(lenValue).    var len = O.length >>> 0;    // 4. If isCallable(callback) is false, throw a TypeError exception.     // See: http://es5.github.com/#x9.11    if (typeof callback !== "function") {      throw new TypeError(callback + ‘ is not a function‘);    }    // 5. If thisArg was supplied, let T be thisArg; else let    // T be undefined.    if (arguments.length > 1) {      T = thisArg;    }    // 6. Let k be 0    k = 0;    // 7. Repeat, while k < len    while (k < len) {      var kValue;      // a. Let Pk be ToString(k).      //    This is implicit for LHS operands of the in operator      // b. Let kPresent be the result of calling the HasProperty      //    internal method of O with argument Pk.      //    This step can be combined with c      // c. If kPresent is true, then      if (k in O) {        // i. Let kValue be the result of calling the Get internal        // method of O with argument Pk.        kValue = O[k];        // ii. Call the Call internal method of callback with T as        // the this value and argument list containing kValue, k, and O.        callback.call(T, kValue, k, O);      }      // d. Increase k by 1.      k++;    }    // 8. return undefined  };}

JavaScript 实现数组的foreach