无临时变量交换两数的操作

int a=1,b=2;

b=a+(a=b)-a;

//以上语句相当于以下三步:

//b=a+b;

//a=b;

//b=b-a;

System.out.println(a +"," + b);

a=1;

b=2;

b=a*b/(a=b/a);

System.out.println(a +"," + b);

a=1;

b=2;

a=a^b;

b=a^b;//利用异或的特性，某数对另一数双次异或后返回原数

a=a^b;//同理

System.out.println(a +"," + b);