意外令牌：使用map形成对象数组[重复]

Question

我想制作这个

[
        {name: "james", age: 10},
        {name: "john", age: 12},
        {name: "johnny", age: 56}
    ]

我下面的代码失败了，得到预期的令牌了吗？

let x = [
    {name: "james", age: 10, school: "London"},
    {name: "john", age: 12, school: "India"},
    {name: "johnny", age: 56, school: "USA"}
]

let y = x.map(obj => {name:obj.name, age:obj.age})

console.log(y)

Answer 1

作为参考，这同样有效：

let x = [
    {name: "james", age: 10, school: "London"},
    {name: "john", age: 12, school: "India"},
    {name: "johnny", age: 56, school: "USA"}
];

let y = x.map(obj => {
  return { name:obj.name, age:obj.age };
});

console.log(y);

Answer 2

使用箭头表达式创建对象时，需要将主体包装在paren中，否则它将被解析为箭头函数：

let y = x.map(obj => ({name: obj.name, age: obj.age}));

Answer 3

你错过了（）这样的更改（{name：obj.name， age：obj.age}）

您必须将返回的对象文字包装到括号中。否则，大括号将被视为表示函数的主体。下一个作品：

参考问题

let x = [
    {name: "james", age: 10, school: "London"},
    {name: "john", age: 12, school: "India"},
    {name: "johnny", age: 56, school: "USA"}
]

let y = x.map(obj => ({name:obj.name, age:obj.age}))

console.log(y)