体会函数参数传递

#include <iostream>  using namespace std;  void jiaohuan(int x, int y);int main(void){int  a,b;cin>>a>>b;if (a<b) jiaohuan(a, b); cout<<"a,b="a<<","<<b;return 0;}void jiaohuan(int x, int y){int t;t=x; x=y; y=t;}

交换函数对a，b的值没能产生影响 没有返回a，b的值所以a，b的值没有交换

 #include <iostream> 
using namespace std; 
void jiaohuan(int *x, int *y);
int main(void)
{
 int  a,b;
 cin>>a>>b;
 if (a<b) jiaohuan(&a, &b);
 cout<<"a,b="<<a<<","<<b;
 return 0;
}
void jiaohuan(int *x, int *y)
{
 int t;
 t=*x;
 *x=*y;
 *y=t;
}