以JSON格式从核心数据中获取特定项目

{
  "employees": [
    {
      "firstName": "John",
      "lastName": "Doe",
      "age": 30,
      "position": "Software Engineer"
    },
    {
      "firstName": "Jane",
      "lastName": "Smith",
      "age": 25,
      "position": "Web Developer"
    }
  ]
}

var data = {
  "employees": [
    {
      "firstName": "John",
      "lastName": "Doe",
      "age": 30,
      "position": "Software Engineer"
    },
    {
      "firstName": "Jane",
      "lastName": "Smith",
      "age": 25,
      "position": "Web Developer"
    }
  ]
};

var lastName = data.employees[0].lastName;
console.log(lastName); // 输出：Doe