es6--扩展运算符

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<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <script>
        /**
         *扩展运算符
         *
         * */
        function show(...a) {
            console.log("a", a);
        }
        //收缩
        show(1, 2, 3, 4)
        //展开
        let arr = [1, 2, 3, 4];
        console.log("arr", ...arr);
        //剩余预算符
        function add(a, b, ...c) {
            console.log("add", a, b, c);
        }

        add(1, 2, 3, 4)
        //对象不可以
        // let obj = {
        //     a: 1,
        //     b: 2,
        //     c: 3
        // }
        // console.log("obj", ...obj);

        let arrb = [...arr];//复制数组
        //箭头函数没有arguments对象
        //箭头函数改变this的作用域
        //参数对象可以用...args
        //箭头函数不能当构造函数用,不能new

    </script>
</head>

<body>

</body>

</html>
let obj1 = {
            name: "a",
            age: 1
        }

        let obj2 = {
            address: "吉林",
            name: "b"

        }

        let obj3 = { ...obj1, ...obj2 };
        console.log("obj3", obj3);
       //对象合并,后边的会覆盖前边的对象
原文地址:https://www.cnblogs.com/jentary/p/13334611.html