js的map

const users = [
  { name: 'Alice', age: 20 },
  { name: 'Bob', age: 25 },
  { name: 'Charlie', age: 30 }
];

// 提取所有用户的姓名，生成新数组
const names = users.map(user => user.name);
console.log(names); // ['Alice', 'Bob', 'Charlie']

// 对对象进行转换（添加新属性）
const usersWithBirthYear = users.map(user => ({
  ...user,
  birthYear: 2024 - user.age // 假设当前年份是 2024
}));
console.log(usersWithBirthYear);
// [
//   { name: 'Alice', age: 20, birthYear: 2004 },
//   { name: 'Bob', age: 25, birthYear: 1999 },
//   { name: 'Charlie', age: 30, birthYear: 1994 }
// ]