function_pointer

function_pointer.c

#include <stdio.h>

typedef int (*g)(int, int);

//function宣告
int doAdd(int, int);
int doMinus(int, int);

g table[] = {
	doAdd,
	doMinus
};

int main(void) {
	//宣告 function pointer
	//注意所設定的參數數量與型態
	g my_func_ptr;

	//function pointer 指向 doAdd
	// my_func_ptr = doAdd;
	 my_func_ptr = table[0];
	printf("function pointer 指向 doAdd => %d\n", (*my_func_ptr)(5, 3));    //結果：8

	//function pointer 指向 doMinus
	my_func_ptr = table[1];
	printf("function pointer 指向 doMinus => %d\n", table[1](5, 3));  //結果：2

	return 0;
}   //end main


int doAdd(int a, int b) {
	return a + b;
}   //end doAdd

int doMinus(int a, int b) {
	return a - b;
}   //end doMinus