Several ways to exchange the values of two variables

1. Borrow a temporary value to exchange two variables:

#include <stdio.h>
int main()
{
    int num1 = 5;
    int num2 = 8;
    int temp;//申请一个临时变量
    printf("num1和num2的值为%d %d\n", num1, num2);
    temp = num1;
    num1 = num2;
    num2 = temp;
    printf("num1和num2的值为%d %d\n", num1, num2);
    return 0;
}

2. Without temporary variables, exchange two variables:

**虽然不用借用临时变量，但是这种计算可能会导致越界
#include <stdio.h>
int main()
{
    int num1 = 5;
    int num2 = 8;
    printf("num1和num2的值为%d %d\n", num1, num2);
    num1 = num2 + num1;
    num2 = num1 - num2;
    num1 = num1 - num2;
    printf("num1和num2的值为%d %d\n", num1, num2);
    return 0;
}

3. Exchange two variables with XOR^:

#include <stdio.h>
int main()
{
    int num1 = 5;
    int num2 = 8;
    printf("num1和num2的值为%d %d\n", num1, num2);
    num1 = num1^num2;
    num2=num1^num2;
    num1 = num1^num2;
    printf("num1和num2的值为%d %d\n", num1, num2);
    return 0;
}

4. Use pointers to exchange two variable values:

#include<stdio.h>
int main()
{
    int num1 = 5;
    int num2 = 8;
    int temp;
    int *p1=&num1;
    int *p2 = &num2;
    printf("num1和num2的值为%d %d\n", num1, num2);
    printf("*p1和*p2的值为%d %d\n", *p1, *p2);
    temp = *p1;
    *p1 = *p2;
    *p2 = temp;
    printf("num1和num2的值为%d %d\n", num1, num2);
    printf("*p1和*p2的值为%d %d\n", *p1, *p2);
    return 0;
}