SOURCE

function at(object, arr) {
  let ret = [];
  for (let i = 0; i < arr.length; i++) {
      let temp = [], ind;
      temp[0] = object[arr[i][0]];
      for (let k = 1; k < arr[i].length; k++) {
          if (arr[i][k] != '[' && arr[i][k] != ']' && arr[i][k] != '.') {
              ind++;
              temp[ind] = temp[ind - 1][arr[i][k]];

          }
      }
    ret.push(temp[ind]);
  }
  return ret;
}

const object = {
  'a': [
    {
      'b': {
        'c': 3,
      },
    },
    4,
  ],
};

// 输出 [3, 4]
console.log(at(object, ['a[0].b.c', 'a[1]']));