https://numb86-tech.hatenablog.com/entry/2016/10/27/123806
Object.assignの返り値意味なくね?
let obj1 = {value1: 'hoge'}; let obj2 = {value2: 'fuga'}; let obj3 = Object.assign(obj1, obj2); console.log(obj1); console.log(obj2); console.log(obj3); obj1.value1 = 'bar'; console.log('=================================='); console.log(obj1); console.log(obj2); console.log(obj3);
obj1とobj3同じ?
console.log(obj3 === obj1); => true
https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Global_Objects/Object/assign 戻り値としてコピー先オブジェクトを返します。
let obj = {value1: 'hoge'}; let obj3 = Object.assign({}, obj2);
みたいにObject.assign
の第一引数が定義してないときに使いたいときは要るかも?