Beginner char Menu function

[FoaaD2506]

I'm still not that with functions,i know i'm doing something wrong here. i'm trying to write a menu function that the user has to enter a character and if statement checks what the user chose and redirects them.
when i enter any of the options it just exits!?
what am i doing wrong?

#include <iostream>
using namespace std;

main()
{
char choice;
menu(choice);
if(choice=='A'){
//do A
}
else
if(choice=='B'){
//do B
}
...

return 0;
}
  char menu(char c)
{
    cout<<"A.Count Vowels Characters"<<endl;
    cout<<"B.Find Cos(X)"<<endl;
    cout<<"C.Print a triangle"<<endl;
    cout<<"D.Average of Primes"<<endl;
    cout<<"E.Exit"<<endl;
    cin>>c;
    return c;
}

[salem c]

> menu(choice);

...

> char menu(char c)
..
> return c;

When you return something, the caller needs to be part of an assignment or comparison to make use of the returned value.

So perhaps
choice = menu(choice);

But passing a parameter as a substitute for a local variable is a poor way to go.

#include <iostream>
using namespace std;
char menu(void)
{
    char c;
    cout<<"A.Count Vowels Characters"<<endl;
    cout<<"B.Find Cos(X)"<<endl;
    cout<<"C.Print a triangle"<<endl;
    cout<<"D.Average of Primes"<<endl;
    cout<<"E.Exit"<<endl;
    cin>>c;
    return c;
}

int main()
{
char choice;
choice = menu();
if(choice=='A'){
//do A
}
else
if(choice=='B'){
//do B
}
...

return 0;
}

[FoaaD2506]

so what do you propose is a better way to go about it ?

[againtry]

#include <iostream>
using namespace std;

void function_A()
{
    cout << "Do something *** AAA *** ...\n";
    return;
}

void function_B()
{
    cout << "Do something *** BBB *** ...\n";
    return;
}

void displayMenu()
{
    cout << "\nPLEASE SELECT FROM\n";
    cout<<"A.Count Vowels Characters"<<endl;
    cout<<"B.Find Cos(X)"<<endl;
    cout<<"C.Print a triangle"<<endl;
    cout<<"D.Average of Primes"<<endl;
    cout<<"E.Exit\n";
    return;
}

char select_item()
{
    char aSelection{};
    cin >> aSelection;
    
    aSelection = toupper(aSelection);
    
    switch( aSelection)
    {
        case 'A':
            function_A();
            break;
        case 'B':
            function_B();
            break;
        case 'E':
            break;
        default:
            cout << "Invalid choice\n";
    }
    return aSelection;
}

int main()
{
    char selection{};
    
    while(selection != 'E')
    {
        displayMenu();
        selection = select_item();
    }
    cout << "The end\n";
    
    return 0;
}

[FoaaD2506]

Thanks :)