c语言响应键盘输入

#include <conio.h>
#include <stdio.h>
int main()
{
	int key=0;
	while(key=getch())
	{
		//printf("%c",key);
		switch(key)
		{
		case 'a':printf("left ");break;
		case 's':printf("down ");break;
		case 'd':printf("right ");break;
		case 'w':printf("up ");break;
		}
	}

}