問題描述

比如這里target = Object(target)和target = Object()或者target = new Object()有什么區別？

if (typeof Object.assign != ’function’) { Object.assign = function(target) { ’use strict’; if (target == null) { throw new TypeError(’Cannot convert undefined or null to object’); } target = Object(target); for (var index = 1; index < arguments.length; index++) { var source = arguments[index]; if (source != null) {for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; }} } } return target; };}

問題解答

你不給參數的話他就是個空對象。。。

https://developer.mozilla.org...這篇文章講得很清楚