不利用临时变量，交换两个变量的值

public class ChangeValue
{

/**
* <不用第三个变量，交换两个变量的值>
*/
public static void main(String[] args)
{
//方法一  精简,一行代码搞定
int x = 3, y = 7, t = 123;
System.out.printf("x = %d, y = %d\n", x, y);
x = y + 0 * (y = x);
System.out.printf("x = %d, y = %d\n", x, y);

//方法二   简单明了
int p = 4, q = 9;
System.out.printf("p = %d, q = %d\n", p, q);
p = p + q; //7
q = p - q; // 7-5=2  q == p
p = p - q; //7-2
System.out.printf("p = %d, q = %d\n", p, q);

//方法三  兼容,支持Integer.MAXVALUE的+操作
int a = 2, b = 5;
System.out.printf("a = %d, b = %d\n", a, b);
a ^= b;
b ^= a;
a ^= b;
System.out.printf("a = %d, b = %d\n", a, b);

//方法四  字符串 数组
String s1 = "111", s2 = "222";
System.out.printf("s1 = %s, s2 = %s\n", s1, s2);
s1 = s1 + "," + s2;
s2 = s1;
s1 = s1.split(",")[1];
s2 = s2.split(",")[0];
System.out.printf("s1 = %s, s2 = %s\n", s1, s2);

//方法五  字符串 表达式（类似方法一）
String str1 = "aaa", str2 = "bbb";
System.out.printf("str1 = %s, str2 = %s\n", str1, str2);
str1 = str2 + ((str2 = str1) == "" ? "" : "");
System.out.printf("str1 = %s, str2 = %s\n", str1, str2);
}

}