1 定义一个变量
let a = 1,
b = 2,
tmp = '';
tmp = a;
a = b;
b = tmp;
2 算术运算
let a = 1,
b = 2;
a = a + b;
b = a - b;
a = a - b;
3 异或运算(会进行二进制转换)
let a = 1,
b = 2;
a = a ^ b;
b = a ^ b;
a = a ^ b;
4 ES6语法
let a = 1,
b = 2;
[a, b] = [b, a];
5 数组特性转换
let a = 1,
b = 2;
a = [a, b];
b = a[0];
a = a[1];
6 数组加运算符(优先级)
let a = 1,
b = 2;
a = [b, b =a][0]
