标签:代码段 and turn 今天 not his amp increase rand
今天在做项目中遇到一个问题,就是forEach 不兼容IE8;后经查阅资料完美解决问题。
资料:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach?v=example
1 //官网查询的兼容代码段 2 // Production steps of ECMA-262, Edition 5, 15.4.4.18 3 // Reference: http://es5.github.io/#x15.4.4.18 4 if (!Array.prototype.forEach) { 5 6 Array.prototype.forEach = function(callback/*, thisArg*/) { 7 8 var T, k; 9 10 if (this == null) { 11 throw new TypeError(‘this is null or not defined‘); 12 } 13 14 // 1. Let O be the result of calling toObject() passing the 15 // |this| value as the argument. 16 var O = Object(this); 17 18 // 2. Let lenValue be the result of calling the Get() internal 19 // method of O with the argument "length". 20 // 3. Let len be toUint32(lenValue). 21 var len = O.length >>> 0; 22 23 // 4. If isCallable(callback) is false, throw a TypeError exception. 24 // See: http://es5.github.com/#x9.11 25 if (typeof callback !== ‘function‘) { 26 throw new TypeError(callback + ‘ is not a function‘); 27 } 28 29 // 5. If thisArg was supplied, let T be thisArg; else let 30 // T be undefined. 31 if (arguments.length > 1) { 32 T = arguments[1]; 33 } 34 35 // 6. Let k be 0. 36 k = 0; 37 38 // 7. Repeat while k < len. 39 while (k < len) { 40 41 var kValue; 42 43 // a. Let Pk be ToString(k). 44 // This is implicit for LHS operands of the in operator. 45 // b. Let kPresent be the result of calling the HasProperty 46 // internal method of O with argument Pk. 47 // This step can be combined with c. 48 // c. If kPresent is true, then 49 if (k in O) { 50 51 // i. Let kValue be the result of calling the Get internal 52 // method of O with argument Pk. 53 kValue = O[k]; 54 55 // ii. Call the Call internal method of callback with T as 56 // the this value and argument list containing kValue, k, and O. 57 callback.call(T, kValue, k, O); 58 } 59 // d. Increase k by 1. 60 k++; 61 } 62 // 8. return undefined. 63 }; 64 } 65 //此处放兼容代码 66 /*兼容代码*/ 67 //resultArr数组 68 resultArr.forEach(function (iterm, index) { 69 //内容 70 })
标签:代码段 and turn 今天 not his amp increase rand
原文地址:http://www.cnblogs.com/jingaier/p/7064210.html