case001:Learning C Language......

learning c language,1 lesson per day,keep on,do more practise.

origin:

#include <stdio.h>
main()
{
 int a,b;
 a=2;b=5;
 swap(a,b);
 printf("a=%d,b+%d\n",a,b);
}
  swap(x,y)
  int x,y;
{
 int t;
 t=x;
 x=y;
 y=t;
 printf("x=%d,y=%d\n",x,y);
}

finished

#include <stdio.h>
void swap(int x, int y); //先声明
int main() //main()
{
 int a,b;
 a=2;b=5;
 swap(a,b);
 printf("a=%d,b=%d\n",a,b);//printf("a=%d,b+%d\n",a,b);
 return 0;
}
/*  swap(x,y)
  int x,y;
  这是古老的函数定义方式
*/
void swap(int x, int y)
{
 int t;
 t=x;
 x=y;
 y=t;
 printf("x=%d,y=%d\n",x,y);
}