记录JavaScript变量对调的七种方法

临时变量

let a = 3,
    b = 5,
    c = b;
b = a;
a = c;

加减法

var a = 3,
    b = 5;
a = a + b;   //a=3+5=8
b = a - b;   //b=8-5=3
a = a - b;   //a=8-3=5

数组索引值

var a = 3,
    b = 5;
a = [a,b]
b = a[0]
a = a[1]

对象

var a = 3,
    b = 5;
a = {a:b,b:a}
b = a.b
a = a.a

数组运算法

var a = 3,
    b = 5;
a = [b,b=a][0]

按位异或

var a = 3,
    b = 5;
a = a ^ b;
b = b ^ a;
a = a ^ b;

a   0011

b   0101

求异或，相同位置的值不相同 结果为 1 ，相同结果为0 所以：

a=a^b=0011^0101= 0110=6

b=b^a=0101^0110=0011=3

a=a^b=0110^0011=0101=5

解构赋值法

var a = 3,
    b = 5;
[b,a]=[a,b]