通过传地址，传引用交换两个数的值

 

#include <cstdio>
#include <iostream>
using namespace std;

void swapxy(char *a ,char *b)
{
    int c = *a;
    *a = *b;
    *b = c;
}
void swapxy(char &a,char &b)
{
    int c = a;
    a = b;
    b = c;
}


int main()
{
    char a = 'f';
    char b = 'g';
    
    swapxy(&a,&b);
    printf("a = %c, b = %c\n",a,b);

    char &x = a;
    char &y = b;

    swapxy(x,y);
    printf("a = %c, b = %c\n",a,b);

    return 0;
}