Thread: Need help with this loop

Code:

#include <iostream>

using namespace std;

int main()
{
    
    
    while (true)
    {
        char op;
        float num1, num2;  
        char ex; 

        cout << "Select + for addition" << endl; // Give the user the option for addition 
        cout << "Select - for subtraction" << endl; // Give the user the option for subtraction 
        cout << "Select * for multiplication" << endl; // Give the user the option for multiplication 
        cout << "Select / for division" << endl; // Give the user the option for division 
        cout << "Select x to exit" << endl; // Give the user the option to exit the program 
        cin >> op; // User selects from the given operations

        if (op == 'x')
        {
            cout << "Are you sure you would like to exit?" << endl;
            cout << "Enter y to exit" << endl;
            cout << "Enter n to stay" << endl;
            cin >> ex;
        }
        
        cout << "Enter number one "; // User enters first number which they want to calculate 
        cin >> num1;

        cout << "Enter number two "; // User enters second number which they want to calculate 
        cin >> num2;

        if (op == '+')
        {
            cout << "Sum of operation = " << num1 + num2 << endl;

        }
        else if (op == '-')
        {
            cout << "Sum of operation = " << num1 - num2 << endl;
        }
        else if (op == '*')
        {
            cout << "Sum of operation = " << num1 * num2 << endl;
        }
        else if (op == '/')
        {
            cout << "Sum of operation = " << num1 / num2 << endl;
        }
        
    }
    system("pause");
    return 0;
    
}

when i ask theuser if they with to exit and they select "x" i am then asking another question but im not sure where to go from there. if they select "y" i want them to exit the program however if they select "n" i want them to go back to the menu were they select their operation again and im not sure how to do this??

Without having put much thought into this, here is a quick solution:

Code:

if (op == 'x')
{
    cout << "Are you sure you would like to exit?" << endl;
    cout << "Enter y to exit" << endl;
    cout << "Enter n to stay" << endl;
    cin >> ex;
    if (ex == 'y') {
        break; // leaves the parent while-loop
    } else {
        continue; // skips remaining loop into next iteration
    }
}

thank you i didn't realise i could have an if inside another if. would you know how i could include a thing were if the user tries to divide by zero a error would come up saying "cannot divide by zero" and would send the user back to the main menu?

You could try that yourself as an exercise! Place an extra check inside the else-if section for division. If the user tries to divide by 0, you could then print a message and go to the next iteration of the loop as in my earlier example.

Code:

else if (op == '/') 
        {
            if (num2 == '0') 
            {
                cout << "Cannot divide by zero" << endl; 
            }
            else 
            {
                cout << "Sum of operation = " << num1 / num2 << endl;  
            }
        }
        else // If op choice is not valid
        {
            cout << "Not a valid choice" << endl; // Tell user thier choice is not valid
            continue; // Continues with the while loop
        }

this is what i managed to do however when i try to divide by 0 the message doesnt show up and im not sure why

Code:

if (num2 == 0) { // not '0'

However, comparing a float to 0 isn't quite as simple as that either, so I would recommend you declare num2 as an integer (num1 can stay float). It's complicated