Question

I am using this program to implement Mono alphabetic cipher. The problem i am getting is when i input plain text it doesn’t get out of the loop when condition is met which is pressing the enter key.Here is my code.

int main()
{
    system("cls");
    cout << "Enter the plain text you want to encrypt";
    k = 0;
    while(1)
    {
        ch = getche();
        if(ch == '\n')
        {

            break; // here is the problem program not getting out of the loop
        }
        for(i = 0; i < 26; i++)
        {
            if(arr[i] == ch)
            {
                ch = key[i];
            }
        }
        string[k] = ch;
        k++;
    }
    for(i = 0;i < k; i++)
    {
        cout << string[i];
    }
    getch();
    return 0;
}

Answer 1

Here the problem is probably the fact that getche() (unlike getchar()) just returns the first character when there are more then one inputed and you are on windows (othewise you wouldn’t use cls) then the EOL is encoded with \r\n.

What happens is that getche() returns \r so your break is never actually executed. You should change it to getchar() even because getche is a non standard function.

You can even try to look for \r instead that \n in your situation but I guess the \n would remain in the buffer causing problems if you need to fetch any additional input later (not sure about it).