使用JavaScript的map方法和索引高效更新对象数组

const lastNames = ["Smith", "Anderson"];

const employees = [
  {
    name: "Jim",
    familyName: "",
  },
  {
    name: "Jill",
    familyName: "",
  }
];

[
  {
    name: "Jim",
    familyName: "Smith",
  },
  {
    name: "Jill",
    familyName: "Anderson",
  }
]

/**
 * 更新员工数组中每个员工的家庭名。
 *
 * @param {Array<Object>} employees - 原始员工对象数组，每个对象应包含name属性。
 * @param {Array<string>} lastNames - 包含家庭名的字符串数组，其索引应与employees数组对应。
 * @returns {Array<Object>} 一个新的员工对象数组，其中每个员工的familyName属性已更新。
 */
function updateEmployeeFamilyNames(employees, lastNames) {
  // 使用 map 方法遍历 employees 数组
  return employees.map(function(employee, index) {
    // employee: 当前遍历到的员工对象
    // index: 当前员工对象在数组中的索引

    // 从 lastNames 数组中根据索引获取对应的家庭名
    const newFamilyName = lastNames[index];

    // 使用展开语法创建一个新的员工对象
    // {...employee} 复制了原始 employee 对象的所有属性
    // familyName: newFamilyName 覆盖或添加了 familyName 属性
    return { ...employee, familyName: newFamilyName };
  });
}

// 原始数据
const lastNames = ["Smith", "Anderson", "Doe"]; // 假设有更多姓氏
const employees = [
  {
    name: "Jim",
    familyName: "",
  },
  {
    name: "Jill",
    familyName: "",
  },
  {
    name: "John",
    familyName: "",
  }
];

// 调用函数更新数据
const updatedEmployees = updateEmployeeFamilyNames(employees, lastNames);

// 打印结果
console.log(updatedEmployees);

/*
预期输出:
[
  { name: 'Jim', familyName: 'Smith' },
  { name: 'Jill', familyName: 'Anderson' },
  { name: 'John', familyName: 'Doe' }
]
*/

// 验证原始 employees 数组未被修改
console.log(employees);
/*
预期输出:
[
  { name: 'Jim', familyName: '' },
  { name: 'Jill', familyName: '' },
  { name: 'John', familyName: '' }
]
*/