c语言 函数指针运用

#include <stdio.h>

//函数声明
int sum(int, int);
int product(int, int);
int different(int, int);

//c语言就是由许多函数组成的,其中main是执行的起点,函数之间互相调用
int main() {
	printf("函数指针使用方法:\n");
	int a = 10, b = 5;
	int result = 0;
	int (*pfun)(int, int); //声明一个函数指针

	pfun = sum; //指针传递
	result = pfun(a, b);
	printf("result: %d\n", result);

	pfun = different;
	result = pfun(a, b);
	printf("result: %d\n", result);

	pfun = product;
	result = pfun(a, b);
	printf("result: %d\n", result);
	printf("\n");

	//函数指针数组
	int (*pfuns[3])(int, int); //声明一个函数指针数组   指针是一个变量,函数指针可以像其他变量一样使用
	pfuns[0] = sum;
	pfuns[1] = different;
	pfuns[2] = product;
	int i = 0;
	while (i < 3) {
		result = pfuns[i](a, b);
		printf("result: %d\n", result);
		i++;
	}

	return 0;
}

int sum(int x, int y) {
	return x + y;
}

int product(int x, int y) {
	return x * y;
}

int different(int x, int y) {
	return x - y;
}