实现深拷贝最简单的方法！

function deepCopy(obj) {

          let _obj = JSON.stringify(obj);
          let objClone = JSON.parse(_obj);

          return objClone

      }

      let arr = [0, 1, 2],
          arrClone = deepCopy(arr)
          arrClone[1] = 2
      console.log(arr)
      console.log(arrClone)