javaScript Object对象方法fromEntries

作用：与entries相反，把键值对列表转换成对象

一、Map对象转Object

const map = new Map([ ['age', 18], ['name', 'zg'] ]);
const obj = Object.fromEntries(map);
console.log(obj); 
// { age: 18, name: 'zg' }

二、Array对象转Object

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