Thread: Why does my program only continue on hitting a key + Enter

Hi,
Can someone tell me why this (otherwise working) program isnt continuing all by its own, but only when I hit a key and Enter?
Thanks

In the following line:

Code:

scanf("%d\n", &n);

Because you included the newline character in scanf() you must enter that character complete the function.

Jim

Yep. From scanf documentation: scanf - C++ Reference

Whitespace character: the function will read and ignore any whitespace characters (this includes blank spaces and the newline and tab characters) which are encountered before the next non-whitespace character. This includes any quantity of whitespace characters, or none.

Scanf won't start trying to match the pattern until the first time you hit enter. "%d\n" will match the number and the newline, but then due to the above quote, it'll keep matching whitespace until you put a non whitespace character in (another key and enter).

Very irritating, I hate scanf.

If you just use %d, a newline will be left waiting on stdin and will mess up subsequent user inputs. You can getchar() it after the scanf, or you could read a char in scanf and throw it away (see * in the link).

Thanks a lot to both of you Jim and smokeyangel!