if (!String.prototype.startsWith) {  Object.defineProperty(String.prototype, 'startsWith', {    enumerable: false,    configurable: false,    writable: false,    value: function (searchString, position) {      position = position || 0;      return this.indexOf(searchString, position) === position;    }  });} //大拿拿了一个这样的代码出来，你妈，，吓死我了，，这不科学啊 而且  this.indexOf(searchString, position) === position;这句感觉有问题