如何从Object中的子项中获取父键

function getParentKey(obj, childKey, parentKey = '') {
  for (let key in obj) {
    if (typeof obj[key] === 'object') {
      if (key === childKey) {
        return parentKey;
      } else {
        let result = getParentKey(obj[key], childKey, key);
        if (result !== '') {
          return result;
        }
      }
    }
  }
  return '';
}

// 示例对象
const obj = {
  key1: {
    key2: {
      key3: 'value3',
      key4: 'value4'
    },
    key5: 'value5'
  },
  key6: {
    key7: {
      key8: 'value8'
    }
  }
};

// 获取子项 'key3' 的父键
const parentKey = getParentKey(obj, 'key3');
console.log(parentKey); // 输出 'key2'