Object.fromEntries()

键值对列表转换为一个对象，与 Object.entries() 相对的（互逆）

const entries = new Map([
    ["key1", "value1"],
    ["key2", "value2"],
]);
const obj = Object.fromEntries(entries);
console.log(obj); // { key1: 'value1', key2: 'value2' }

Map 转化为 Object

const map = new Map([
    ["foo", "bar"],
    ["baz", 42],
]);
// const map = new Map();
// map.set('key1','value1')
// map.set('key2','value2')
const obj = Object.fromEntries(map);
console.log(obj); // { key1: 'value1', key2: 'value2' }

Array 转化为 Object

const arr = [
    ["0", "a"],
    ["1", "b"],
    ["2", "c"],
];
const obj = Object.fromEntries(arr);
console.log(obj); // { 0: 'a', 1: 'b', 2: 'c' }

对象转换

const course = {
    abc: 1,
    def: 2,
    ghksks: 3,
};
const res = Object.fromEntries(
    Object.entries(course).filter(([key, val]) => key.length === 3)
);
console.log(res);