C语言进阶:指针的进阶(5)

目录

• 函数指针数组

• 函数指针数组的定义
• 函数指针数组的使用
• 转移表
• 回调函数
• 指向函数指针数组的指针

//整型数组 - 存放整型变量
int arr[10];
//字符数组 - 存放字符变量
char ch[5];
//指针数组 - 存放指针变量
int* arr[10];
//函数指针数组 - 存放函数指针
int(*pfar[10])(int, int);

int Add(int x, int y) {//int(*)(int,int)
	return x + y;
}
int Sub(int x, int y) {//int(*)(int,int)
	return x - y;
}
int Mul(int x, int y) {//int(*)(int,int)
	return x * y;
}
int Div(int x, int y) {//int(*)(int,int)
	return x / y;
}
int main() {
	//函数指针数组 - pfArr
	int(*pfArr[4])(int, int) = { Add,Sub,Mul,Div };
	return 0;
}

//计算器实现1.0
void menu() {
	printf("**********************************\n");
	printf("*****  1.Add  ******  2.Sub  *****\n");
	printf("*****  3.Mul  ******  4.Div  *****\n");
	printf("************  0.exit  ************\n");
	printf("**********************************\n");
}
int main() {
	int (*pfArr[10]) (int, int) = { 0,Add,Sub,Mul,Div };//数组下标和选项序号匹配
	int input = 0;
	int a = 0;
	int b = 0;
	do {
		menu();
		printf("请选择:>");
		scanf("%d", &input);
		if (0 <= input && input <= 4) {
			if (input == 0) {
				printf("退出游戏\n");
				break;
			}
			else {
				printf("请输入操作数\n");
				scanf("%d %d", &a, &b);
				printf("ret == %d\n", pfArr[input](a, b));
				break;
			}
		}
		else {
			printf("输入错误\n");
			break;
		}
	} while (input);
	return 0;
}

/******
* 计算器实现
* 2.0
******/
void Calc(int (*pf)(int,int)) {
	int a = 0;
	int b = 0;
	printf("请输入操作数:>");
	scanf("%d %d", &a, &b);
	printf("%d\n", pf(a, b));
}
int main() {
	int input = 0;
	do {		menu();
		printf("请选择:>");
		scanf("%d", &input);
		switch (input) {
		case 0:
			printf("退出成功\n");
			break;
		case 1:
			Calc(Add);
			break;
		case 2:
			Calc(Sub);
			break;
		case 3:
			Calc(Mul);
			break;
		case 4:
			Calc(Div);
			break;
		default:
			printf("请重新选择\n");
			break;
		}
	} while (input);
	return 0;
}
/******
* 计算器实现
* 3.0
******/
int (*pfArr[10])(int, int) = { 0,Add,Sub,Mul,Div };
int input = 0;
void Call() {
	int a = 0;
  int b = 0;
	printf("请输入操作数:>");
	scanf("%d %d", &a, &b);
	printf("%d\n", pfArr[input](a, b));
}
int main() {
	do {
		menu();
		printf("请选择:>");
		scanf("%d", &input);
		switch (input) {
		case 0:
			printf("退出成功\n");
			break;
		case 1:
		case 2:
		case 3:
		case 4:
			Call();
			break;
		default:
			printf("请重新选择\n");
			break;
		}
	} while (input);
	return 0;
}

int arr[10];
int(*parr)[10] = &arr;//整型数组指针
char(*pch)[10] = &ch;//字符数组指针
//指向整型数组指针的指针
int(*(*pparr))[10] = &parr;
//指向字符数组指针的指针
char(*(*ppch))[10] = &pch;
//函数1.
int Add(int x, int y) {
	return x + y;
}
//函数指针2.
int (*pf)(int, int) = Add;
//函数指针数组3.
int (*pfArr[10])(int, int) = { Add };
//指向函数指针数组的指针4.
int(*(*ppfArr)[10])(int, int) = &pfArr;