回调函数:通过函数指针调用的函数。
#include<stdio.h>
int add(int x, int y)
{
return x + y;
}
int sub(int x, int y)
{
return x - y;
}
int mul(int x, int y)
{
return x * y;
}
int div(int x, int y)
{
return x / y;
}
void menu()
{
printf("1.加、2.减、3.乘、4.除、0.退出\n");
}
void calc(int (*p)(int, int))
{
int x = 0;
int y = 0;
printf("请输入两个数:");
scanf("%d%d", &x, &y);
printf("%d\n", p(x, y));
}
int main()
{
int input = 0;
int (*p[5])(int, int) = {
0,add,sub,mul,div };
do {
menu();
printf("请选择:");
scanf("%d", &input);
switch (input)
{
case 1:
calc(add);
break;
case 2:
calc(sub);
break;
case 3:
calc(mul);
break;
case 4:
calc(div);
break;
case 0:
printf("退出。\n");
break;
default:
printf("输入有误。\n");
break;
}
} while (input);
return 0;
}