Getting limited user input, with echo

Question

I've written a code snippet that will get a (max.) 14 character string from the user input, and while the user is typing, simultaneously echo it out to the screen.

It seems a bit long and ugly, so I was wondering if any of you would happen to have ideas on how to shorten, and generally optimize this.

for(int i = 0; i < 15; i++)
{
 char npt = _getch(); // Get input
 if(i == 14) // Last character (user has to press \r or \b)
 {
 if(npt == '\r') // enter, break loop
 break;
 else if(npt == '\b') // backspace, re-loop
 {
 if(!name.empty())
 name.erase(std::prev(name.end()));
 if(i >= 1)
 i -= 2;
 else
 i--;
 }
 else // other input, meaning re-loop
 i--;
 SetConsoleCursorPosition(hOut, cDraw);
 printf(" "); // clear string area
 SetConsoleCursorPosition(hOut, cDraw);
 std::cout << name; // echo string
 continue;
 }
 else
 {
 if(npt == '\r')
 break;
 else if(npt == '\b')
 {
 if(!name.empty())
 name.erase(std::prev(name.end()));
 if(i >= 1)
 i -= 2;
 else
 i--;
 }
 else
 name += npt; // add input to string
 SetConsoleCursorPosition(hOut, cDraw);
 printf(" ");
 SetConsoleCursorPosition(hOut, cDraw);
 std::cout << name;
 }
}

Answer 1

c++ isn't really my language, but I believe this would be an identical loop:

for(int i = 0; i < 15; i++)
{
 char npt = _getch(); // Get input
 if(npt == '\r')
 break;
 else if(npt == '\b')
 {
 if(!name.empty())
 name.erase(std::prev(name.end()));
 if(i >= 1)
 i -= 2;
 else
 i--;
 }
 else if(i == 14)
 i--;
 else 
 name += npt; // add input to string
 SetConsoleCursorPosition(hOut, cDraw);
 printf(" ");
 SetConsoleCursorPosition(hOut, cDraw);
 std::cout << name;
}

The only difference between your first if and the else is the final else line, so I moved the conditional to the end to avoid repeating the same logic.

Additionally, I assume there's some way you could pad name with blank spaces so that you only have to call SetConsoleCursorPosition and print once per iteration.

• user32926: Hey, that's a really good answer! I'll accept it in a minute. Meanwhile, would you have an idea on how to efficiently do the name padding?
• Daniel: I don't know. But this page seems to provide a possible method. You might ask on StackOverflow if you're unable to find a way after searching.
• user32926: Ok, I'll search around for an answer. Thanks, man.