Calculator (Pointers to functions)

calculator.cpp

#include <iostream> 

int add(int x, int y){ return x + y; }
int multiply(int x, int y){ return x * y; }
int subtract(int x, int y){ return x - y; }
int divide(int x, int y){ return x / y; }

typedef int (*arithmeticFcn)(int, int);

struct arithmeticStruct
{
    char s;
    arithmeticFcn fcn;
};

static arithmeticStruct arithmeticArray[] = {
    { '+', add },
    { '-', subtract },
    { '*', multiply},
    { '/', divide }
};

arithmeticFcn getArithmeticFcn(char s)
{
    for(auto &arith : arithmeticArray)
    {
        if(arith.s == s)
            return arith.fcn;
    }
        return add;
}

int main()
{
    int a;
    int b;
    
    std::cout << "a: ";
    std::cin >> a;
    std::cout << "b: ";
    std::cin >> b;
    char c;
    do 
    {
        std::cout << "Enter an operation ('+', '-', '*', '/'): ";
        std::cin >> c;
        if(c == '+' or c == '-' or c == '*' or c == '/')
            break;
        else
            continue;
    } while(true);
        
    arithmeticFcn fcn = getArithmeticFcn(c);
    
    std::cout << a << ' ' << c << ' ' << b << " = " << fcn(a, b) << '\n';
    
    return 0;
}