int a=1,b=2;
System.out.println("a="+a+" b="+b);
//用位异或实现两个变量值的交换
a=a^b;
b=a^b;
a=a^b;
System.out.println("a="+a+" b="+b);
//用第三方交换
int c=a;
a=b;
b=c;
System.out.println("a="+a+" b="+b);
//用两个数相加减
a=a+b;
b=a-b;
a=a-b;
System.out.println("a="+a+" b="+b);
//一句话搞定
b=(a+b)-(a=b);
System.out.println("a="+a+" b="+b);