09-交换两个变量的值.html

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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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    <script>
        // 1. 这样子没法实现变量的交换
        let n1 = 20, n2 = 30;
        n1, n2 = n2, n1
        console.log(n1, n2)

        // 2. 需要声明一个临时变量
        let tmp
        tmp = n1
        n1 = n2
        n2 = tmp
        console.log(n1, n2)
    </script>
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