function _reverse(number) {
      // 补全代码
    let res = number<0? '-'+reNum(number):reNum(number)
      return Number(res);
      function reNum(num){
          let res = '';
          num = Math.abs(num);
          while(num>0){
              res += (num%10);
              num = Math.floor(num/10);
          }
          return res;
      }
  }