[C++]function_pointer_example2

func_ptr_ex2.cpp

#include <iostream>
#include <conio.h>

using namespace std;

int sum(int a,int b);
int subtract(int a,int b);
int multi(int a,int b);
int divide(int a,int b);

int(*p[4])(int x,int y) = {sum, subtract, multi, divide};

int main()
{
	int result;
	int num1, num2, operNum;
	char oper;
	
	cout << "두 수를 입력하세요 : " ;
	cin >> num1 >> num2;
	cout << "+: 더하기, -: 빼기, *: 곱하기, /: 나누기 " << endl;
	
	
	do
	{
		operNum = -1;
		cout << "연산을 선택하세요 : ";	
		oper = cin.get();	//문자만 입력을 받을 때 cin.get() 사용 		
				
		switch(oper){
			case '+':
				operNum = 0;
				break;
			case '-':
				operNum = 1;
				break;
			case '*':
				operNum = 2;
				break;
			case '/':
				operNum = 3;
				break;
		}		
		
    } while (operNum>3 || operNum<0);
    
    result = (*p[operNum])(num1, num2);
	cout << "연산 결과 : " << result << endl;   
	
	return 0;	 
}

int sum(int a,int b)
{
	return a+b;
}

int subtract(int a,int b)
{
	return a-b;
}

int multi(int a,int b)
{
	return a*b;
}

int divide(int a,int b)
{
	if(a!=0 && b!=0){
		return a/b;
	} else return 0;
	
}