y/n interface

[justinmburrous]

Hey, I am not new to c++, but still learning. As in I dont get pointers but I understand classes, functions, and the other main features of c++, so I will try not to sound like a total noob.

Allright here is my question...

Firstly, I know there are probs better ways to do this, I just want to know why this code isnt working. I want to have a y/n response, (enter a y for yes and a n for no type thing). I cant get this to work though. Any ideas as to why this isnt working?

#include <iostream>

using namespace std;

int main()
{
    char letterSelection;

    cout << "Please enter a y for yes or a n for a no" << endl;
    cout << "slection: ";
    cin >> letterSelection;
    int switchInput;
    if(letterSelection = 'y')
        {
            switchInput = 1;
        }
    else
        {
            switchInput = 2;
        }


    switch(switchInput)
        {
            case 1:
                cout << "You selected yes";
                break;
            case 2:
                cout << "You selected no";
                break;
            default:
                cout << "default";
                break;
        }
    return 0;
}

[Bazzy]

On line 13 you are using the assignment operator, not the comparison ( == )

[justinmburrous]

Allright thanks.
Now that brings me to another question. If I were to use numbers instead of letters. (yes I know I know there is a switch statement and that would be pointless...) But then I could just use an "=" right. Why do I have to use a "==" for this?

[Rabtherab]

= means assignment
== tests for equality

A = 3; // read this as 'assign 3 to A'
A == 1; // read this as 'A is equal to 1'.  Returns FALSE
A == 3; // returns TRUE 

[Skillless]

A == 1; // read this as ' IS A equal to 1'. Returns FALS

[helios]

Rabtherab's reading is technically more accurate.
Relational operators form clauses, not complete questions. Otherwise, "if A==1" would have to be read as "if is A equal to 1?", and "A=A==1" as "A is is A equal to 1?", rather than "if A is equal to 1" and "A is A is equal to 1".

Questions are never made in neither logic nor programming. A question implies that the answer is not known, but state is always known; at least in deterministic computers.

[Rabtherab]

I was going to say something to that effect.

[Rabtherab]

A == 1; // read this as ' IS A equal to 1'. Returns FALS

I would actually read:

if (A == 1) { // If 'A is equal to 1'
     // do something
}

Which is what I think you were driving at.

[marembo]

the assignment in the if clause will always evaluate to true

c++ will assign the 'y' to the letterSelection variable and then implicitly convert it to an integer value (=ascii integral value for character 'y')

now, if an integer is not zero, it is evaluated to true

[justinmburrous]

okay, great. Thanks for all the help