C语言深入浅出分析函数指针

#include<stdio.h>
void test()
{
	printf("haha\n");
}
int main()
{
	printf("%p\n", test);
	printf("%p\n", &test);		
	return 0;
}

#include<stdio.h>
void test()
{
	printf("haha\n");
}
int main()
{
	//函数指针
	int (*pf)(const char*) = test;
	(*pf)("abc");
	pf("abc");
	test("abc");
	return 0;
}

int (*pf)(const char*) = test

void (*signal(int , void(*)(int)))(int);

typedef void(*pfun_t)(int);
pfun_t signal(int, pfun_t);

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
void menu()
{
	printf("*****************\n");
	printf("***1.sum 2.sub***\n");
	printf("***3.mul 4.div***\n");
	printf("*****0.退出*****\n");
	printf("*********\n");
 
}
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;
}
//计算
void calc(int(*pf)(int, int))
{
	int x = 0;
	int y = 0;
	int ret = 0;
	printf("输入两个操作数：");
	scanf("%d%d", &x, &y);
	ret = pf(x, y);
	printf("%d\n", ret);
}
int main()
{
	int input = 0;
	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("退出计算器！\n");
				break;
			default:
				printf("选择错误!\n");
				break;
		}
	} while (input);
	return 0;
}