Question

我有以下代码，但它似乎在IE8中不起作用。我读过IE8并不支持array.prototype.foreach。你怎么能在IE8中解决这个问题？

[].forEach.call(data.Results.cars, function(inst){

   // Fetching the value of key _
   var _html = inst["_"];

   // Fetching the src of image by making string a jquery object
   var _src = $(_html).find("img").attr("src");

   //Extracting the image's name
   var _imagesName = _src.match(/([^\/]+)(?=\.\w+$)/)[0];

   // Building html
   var _h = '<div >'
            +'<img src="'+_src+'" >'
            +'<p>'+_imagesName+'</p>'
            +'<p><input type="radio" value="'+imagesName'" name="cartype"> </p>'
         +'</div>';

   // Appending html to #results
   $("#results").append(_h);

});

Answer 1

IE8不支持

Array#forEach，IE9及更高版本支持

Browser Compatibility，请参阅for

您可以使用来自MDN的polyfill或Wiki

// Production steps of ECMA-262, Edition 5, 15.4.4.18
// Reference: http://es5.github.io/#x15.4.4.18
if (!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
  };
}

Array.prototype.forEach在IE8中不起作用

1 个答案: