JavaScript Object keys 方法

定义对象

const obj = {
    3: "Hello World",
    1: '你好',
    "bbb": "value of bbb",
    "aaa": "value of aaa",
}

Object.keys

只保留key的值

const keys = Object.keys(obj);
console.log(keys);

输出

[
    "1",
    "3",
    "bbb",
    "aaa"
]

映射为 value 的值

等价于Object.values(obj)

const valueArr = Object.keys(obj).map(key => obj[key]);
console.log(valueArr);

输出

[
    "你好",
    "Hello World",
    "value of bbb",
    "value of aaa"
]

映射为新对象

const myObjArr = Object.keys(obj).map(key => ({
    myKey: key,
    myValue: obj[key],
}));
console.log(myObjArr);

输出

[
    {
        "myKey": "1",
        "myValue": "你好"
    },
    {
        "myKey": "3",
        "myValue": "Hello World"
    },
    {
        "myKey": "bbb",
        "myValue": "value of bbb"
    },
    {
        "myKey": "aaa",
        "myValue": "value of aaa"
    }
]