IE 11 不支持 'from' 方法

Question

我的 3000 行代码在 chrome 和 Firefox 中执行得很好，报告的错误为零。

但是，在 IE11 中（代码必须运行），我收到一条错误消息，指出以下行不支持方法“from”：

var inputsArray = Array.from(document.querySelectorAll('input.input' + b));

我该如何解决？

HTML 文件包含正确的边缘兼容模式，所以这不是问题。

Answer 1

简答

使用 polyfill。 Mozilla 在 Array.from 页面上提供了一个。

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/from#Polyfill

进一步帮助

其他可以使用的好网站是检查特定浏览器版本是否提供该功能。

Answer 2

Array.from方法在IE中根本不起作用。检查 MDN 页面的兼容性。

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/from#Browser_compatibility

您可以使用 polyfill 使其工作：

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/from#Polyfill

来自文档：

Array.from was added to the ECMA-262 standard in the 6th edition (ES2015); as such it may not be present in other implementations of the standard. You can work around this by inserting the following code at the beginning of your scripts, allowing use of Array.from in implementations that don't natively support it. This algorithm is exactly the one specified in ECMA-262, 6th edition, assuming Object and TypeError have their original values and that callback.call evaluates to the original value of Function.prototype.call. In addition, since true iterables can not be polyfilled, this implementation does not support generic iterables as defined in the 6th edition of ECMA-262.

这是文档中建议的 polyfill：

// Production steps of ECMA-262, Edition 6, 22.1.2.1
if (!Array.from) {
  Array.from = (function() {
    var toStr = Object.prototype.toString;
    var isCallable = function(fn) {
      return typeof fn === 'function' || toStr.call(fn) === '[object Function]';
    };
    var toInteger = function(value) {
      var number = Number(value);
      if (isNaN(number)) {
        return 0;
      }
      if (number === 0 || !isFinite(number)) {
        return number;
      }
      return (number > 0 ? 1 : -1) * Math.floor(Math.abs(number));
    };
    var maxSafeInteger = Math.pow(2, 53) - 1;
    var toLength = function(value) {
      var len = toInteger(value);
      return Math.min(Math.max(len, 0), maxSafeInteger);
    };

    // The length property of the from method is 1.
    return function from(arrayLike /*, mapFn, thisArg */ ) {
      // 1. Let C be the this value.
      var C = this;

      // 2. Let items be ToObject(arrayLike).
      var items = Object(arrayLike);

      // 3. ReturnIfAbrupt(items).
      if (arrayLike == null) {
        throw new TypeError('Array.from requires an array-like object - not null or undefined');
      }

      // 4. If mapfn is undefined, then let mapping be false.
      var mapFn = arguments.length > 1 ? arguments[1] : void undefined;
      var T;
      if (typeof mapFn !== 'undefined') {
        // 5. else
        // 5. a If IsCallable(mapfn) is false, throw a TypeError exception.
        if (!isCallable(mapFn)) {
          throw new TypeError('Array.from: when provided, the second argument must be a function');
        }

        // 5. b. If thisArg was supplied, let T be thisArg; else let T be undefined.
        if (arguments.length > 2) {
          T = arguments[2];
        }
      }

      // 10. Let lenValue be Get(items, "length").
      // 11. Let len be ToLength(lenValue).
      var len = toLength(items.length);

      // 13. If IsConstructor(C) is true, then
      // 13. a. Let A be the result of calling the [[Construct]] internal method 
      // of C with an argument list containing the single item len.
      // 14. a. Else, Let A be ArrayCreate(len).
      var A = isCallable(C) ? Object(new C(len)) : new Array(len);

      // 16. Let k be 0.
      var k = 0;
      // 17. Repeat, while k < len… (also steps a - h)
      var kValue;
      while (k < len) {
        kValue = items[k];
        if (mapFn) {
          A[k] = typeof T === 'undefined' ? mapFn(kValue, k) : mapFn.call(T, kValue, k);
        } else {
          A[k] = kValue;
        }
        k += 1;
      }
      // 18. Let putStatus be Put(A, "length", len, true).
      A.length = len;
      // 20. Return A.
      return A;
    };
  }());
}

IE 11 不支持 'from' 方法

IE 11 does not support method ‘from’

javascript

internet-explorer-11

简答

进一步帮助