变量交换（多种方法）

1.临时变量法

<script>
    var a = 3;
    var b = 5;
    var c = b;
    b = a;
    a = c;
    console.log(a, b);
  </script>

2.加减法

<script>
    var a = 3;
    var b = 5;
    a = a + b;
    b = a - b;
    a = a - b;
    console.log(a, b);
  </script>

3.数组法

<script>
    var a = 3;
    var b = 5;
    a = [a, b];
    b = a[0];
    a = a[1];
    console.log(a, b);
  </script>

4.对象法

<script>
    var a = 3;
    var b = 5;
    a = {
      a: b,
      b: a,
    };
    b = a.b;
    a = a.a;
    console.log(a, b);
  </script>

5.数组运算法

<script>
    var a = 3;
    var b = 5;
    a = [b, (b = a)][0];
    console.log(a, b);
  </script>

6.按位异或法

<script>
    var a = 3;
    var b = 5;
    a = a ^ b;
    b = b ^ a;
    a = a ^ b;
    console.log(a, b);
  </script>

7.解构赋值法

 <script>
    var a = 3;
    var b = 5;
    [a, b] = [b, a];
    console.log(a, b);
  </script>