Why switch won't execute while condition - c++

Question

Can somebody please explain to me why this code won't execute the while condition?
I just want to know why the code behaves this way or if there are other ways to make it work.Thanks
UPDATE!!!
Hi by the way this is the code, I am not very familiar with C++ so I am not sure while the program skips the while condition on switch. Thanks
#include<iostream>
#include<algorithm>
#include<cstring>
#include<vector>
#define MAX 100
using namespace std;
int main()
{
void remove(char[]);
void add(char[], char);
char cstring[MAX];
char letter;
int ecount;
std::string str;
char selection;
cout << "Enter String: ";
cin.getline(cstring, MAX);
cout << "Size of String: " << strlen(cstring) << endl;
bool gameOn = true;
while (gameOn != false){
cout<<"\n Menu";
cout<<"\n========";
cout<<"\n A - Append";
cout<<"\n X - Exit";
cout<<"\n Enter selection: ";
cin>>selection;
switch(selection)
{
case 'A' :
case 'a' :
cout << " Add Element: ";
while (letter!='\n')
{
letter = cin.get();
add(cstring, letter);
}
cout << "\n Output String: " << cstring;
ecount = strlen(cstring) - 1;
cout << " Size of String: " << ecount<< endl;
break;
case 'X' :
case 'x' :{cout<<"\n To exit the menu";}
break;
default : cout<<"\n !!Invalid selection!!"<< endl;
}
}
cout<<"\n";
return 0;
}
char * add( char *cstring, char c )
{
int letter = strlen( cstring );
if ( letter < MAX - 1 )
{
cstring[letter] = c;
cstring[letter + 1] = '\0';
}
return ( cstring );
}

Answer 1

Its my wild guess.
I think you have to initialize letter.
check it out by using the following code.
And yes debug for the value of selection you are passing to switch too.
switch(selection)
{
case 'A' :
case 'a' :
cout << "Add Element: ";
letter = cin.get(); // this will initialize the char letter;
while (letter != '\n') // or use ascii value of new line char in while condition
{
add(cstring, letter); // first add it to string
letter = cin.get(); // then get next letter
}
cout << "String: " << cstring;
ecount = strlen(cstring) - 1; // ecount must be a int
cout << "Size of String: " << ecount<< endl;
break;
Hope this will help you

Answer 2

The problem is in the input you are reading, When you read a character in the
cin>>selection;
It will read a char and put it into selection and when you press enter it will be get stored in the letter and you'r while loop will never execute.
see the code below it is working fine;
#include<iostream>
#include <stdio.h>
#include <string.h>
#include<algorithm>
#include<cstring>
#include<vector>
#define MAX 100
using namespace std;
int main()
{
void remove(char[]);
void add(char[], char);
char cstring[MAX];
char letter;
int ecount;
std::string str;
char selection;
cout << "Enter String: ";
cin.getline(cstring, MAX);
cout << "Size of String: " << strlen(cstring) << endl;
bool gameOn = true;
while (gameOn != false){
cout<<"\n Menu";
cout<<"\n========";
cout<<"\n A - Append";
cout<<"\n X - Exit";
cout<<"\n Enter selection: ";
cin>>selection;
cout<<"\n selection="<<selection;
switch(selection)
{
case 'A' :
case 'a' :
selection=cin.get();
cout << " Add Element: ";
while (letter!='\n')
{
letter = cin.get();
add(cstring, letter);
}
cout << "\n Output String: " << cstring;
ecount = strlen(cstring) - 1;
cout << " Size of String: " << ecount<< endl;
break;
case 'X' :
case 'x' :cout<<"\n To exit the menu";
gameOn=false;
break;
default : cout<<"\n !!Invalid selection!!"<< endl;
}
}
cout<<"\n";
return 0;
}