ie 兼容

ie 通用兼容问题

大部分的兼容问题可以通过引入polyfill解决

https://polyfill.alicdn.com/polyfill.min.js

兼容ie数组没有findIndex方法

    if (!Array.prototype.findIndex) {
      Object.defineProperty(Array.prototype, 'findIndex', {
        value: function(predicate:any) {
         // 1. Let O be ? ToObject(this value).
          if (this == null) {
            throw new TypeError('"this" is null or not defined');
          }
    
          var o = Object(this);
    
          // 2. Let len be ? ToLength(? Get(O, "length")).
          var len = o.length >>> 0;
    
          // 3. If IsCallable(predicate) is false, throw a TypeError exception.
          if (typeof predicate !== 'function') {
            throw new TypeError('predicate must be a function');
          }
    
          // 4. If thisArg was supplied, let T be thisArg; else let T be undefined.
          var thisArg = arguments[1];
    
          // 5. Let k be 0.
          var k = 0;
    
          // 6. Repeat, while k < len
          while (k < len) {
            // a. Let Pk be ! ToString(k).
            // b. Let kValue be ? Get(O, Pk).
            // c. Let testResult be ToBoolean(? Call(predicate, T, « kValue, k, O »)).
            // d. If testResult is true, return k.
            var kValue = o[k];
            if (predicate.call(thisArg, kValue, k, o)) {
              return k;
            }
            // e. Increase k by 1.
            k++;
          }
    
          // 7. Return -1.
          return -1;
        }
      });
    }
    

ie兼容find方法

if(!Array.prototype.find){
  Array.prototype.find = function(callback) {
      return callback && (this.filter(callback) || [])[0];
  };
}