Converting Letters to numbers (Phone Key Pad)

[Victor714]

Im doing this homework assignment in which i need to convert letters to a number.(like on the telephone key pads, ABC = 2, DEF = 3, etc.

This is my code for ABC(i know it is incorrect,but i need help I dont know what else to do) :

#include<iostream>
 
using namespace std;
 
int main()
 
{
       
        char letter;
        int digit;
       
 
    cout <<"Please enter a single letter in upper case,and I will tell you what the corresponding digit is on the telephone:";
   
        cin  >> letter;
        switch (digit)
        {
       
        case 'A':
        case 'B':
        case 'C':
        digit= 2;
       
        }

[Need4Sleep]

what exactly are you having trouble with? are stuck or just getting compiler errors?

[vlad from moscow]

In fact you already wrote the program except that instead of switch( digit ) you shall use switch ( letter ). For example

#include<iostream>
#include <cctype>
 
using namespace std;
 
int main()
{
       
        char letter;
        int digit;
       
 
        cout <<"Please enter a single letter, and I will tell you what the corresponding digit is on the telephone:";
   
        cin  >> letter;
        letter = toupper( letter );

        switch ( letter )
        {
       
        case 'A': case 'B': case 'C':
        digit= 2;
        cout << digit << " corresponds to " << letter << endl;
        break;

        default:
        cout << letter << " is unknown\n";
        break;       
        }

        return ( 0 );
}

[Victor714]

As you may see im new (not that new to not know what cout and cin does but still new)to c++, what does "toupper" do or has to do in there?

[vlad from moscow]

toupper is a standard C function that converts a letter to upper case. This will allow a user to input either a low case letter or upper case letter. That is your program will be more smart and will convert a letter to upper case itself.