交换两个变量的值

方法一：使用中间变量

temp  = m;

m = n;

n = temp;

int m = 12;
int n = 5;
int temp = m;  //中间变量temp
m = n;
n = temp;
System.out.println("m:" + m + " n:" + n);

方法二：直接在输出的时候交换

int m 12;
int n 5;
System.outt.println("m:" + n + " n:" + m);

方法三：加减法

m = m + n;     //m = 12 + 5;
n = m - n;       //n = 17 - 5;
m = m - n;      //m = 17- 12；

当m和n较大时，有可能出现精度损失

int m = 12;
int n = 5;
m = m + n;
n = m - n;
m = m - n;
System.out.println("m:" + m + " n:" + n);

方法四：乘除法

m = m * n;       //m = 12 * 4

n = m / n;        //n = 48 / 4

m = m / n;       //m = 48 / 4

有可能出现精度损失

int m = 12;
int n = 4;
m = m * n;
n = m / n;
m = m / n;
System.out.println("m:" + m + " n:" + n);

方法五：异或法

m = m ^ n;
n = m ^ n;        //(m ^ n) ^ n == m
m = m ^ n;        //(m ^ n) ^ m == n

	0	0	0	0	1	1	0	0	（m=12）
^	0	0	0	0	0	1	0	1	（n=5）
	0	0	0	0	1	0	0	1	(m^n)

	0	0	0	0	1	0	0	1	(m^n)
^	0	0	0	0	0	1	0	1	（n=5）
	0	0	0	0	1	1	0	0	(m ^ n) ^ n

	0	0	0	0	1	1	0	0	(m ^ n) ^ n
^	0	0	0	0	0	1	0	1	（n=5）
	0	0	0	0	1	0	0	1	(m ^ n) ^ m

int m = 12;
int n = 5;
m = m ^ n;
n = m ^ n;    //(m ^ n) ^ n == m
m = m ^ n;    //(m ^ n) ^ m == n
System.out.println("m:" + m + " n:" + n);