slice（）数组截取；slice（0，-1），截除数组最后一位 原数组改变

  let arr1 = [
        { name: "1322", age: "112" },
        { name: "2322", age: "212" },
        { name: "3322", age: "312" },
      ];
      let arr2 = arr1.slice(0, -1);
      console.log(arr2);//arr2 = [{ name: "1322", age: "112" },{ name: "2322", age: "212" }];
      console.log(arr2);
      console.log(arr2);
    },