ie11對(duì)es6支持的問題

startsWith的mdn，這個(gè)你的看看，ie根本就沒事實(shí)現(xiàn)這個(gè)方法，你既然使用了babel-polyfill，那么你應(yīng)該是看不到startsWith這個(gè)方法的，所以應(yīng)該是沒有被轉(zhuǎn)譯，想想引得babel-polyfill是否正確，考慮使用mdn提供的轉(zhuǎn)譯再寫一遍。

/*! http://mths.be/startswith v0.2.0 by @mathias */
if (!String.prototype.startsWith) {
  (function() {
    'use strict'; // needed to support `apply`/`call` with `undefined`/`null`
    var defineProperty = (function() {
      // IE 8 only supports `Object.defineProperty` on DOM elements
      try {
        var object = {};
        var $defineProperty = Object.defineProperty;
        var result = $defineProperty(object, object, object) && $defineProperty;
      } catch(error) {}
      return result;
    }());
    var toString = {}.toString;
    var startsWith = function(search) {
      if (this == null) {
        throw TypeError();
      }
      var string = String(this);
      if (search && toString.call(search) == '[object RegExp]') {
        throw TypeError();
      }
      var stringLength = string.length;
      var searchString = String(search);
      var searchLength = searchString.length;
      var position = arguments.length > 1 ? arguments[1] : undefined;
      // `ToInteger`
      var pos = position ? Number(position) : 0;
      if (pos != pos) { // better `isNaN`
        pos = 0;
      }
      var start = Math.min(Math.max(pos, 0), stringLength);
      // Avoid the `indexOf` call if no match is possible
      if (searchLength + start > stringLength) {
        return false;
      }
      var index = -1;
      while (++index < searchLength) {
        if (string.charCodeAt(start + index) != searchString.charCodeAt(index)) {
          return false;
        }
      }
      return true;
    };
    if (defineProperty) {
      defineProperty(String.prototype, 'startsWith', {
        'value': startsWith,
        'configurable': true,
        'writable': true
      });
    } else {
      String.prototype.startsWith = startsWith;
    }
  }());
}

解決了,我有個(gè)vendor.js沒有引入babel-polyfill ...