Reading multiple character arrays in C using scanf

Question

  char a[100],b[100],c[100];
  scanf("%[^\n]",a);
  printf("%s",a);
  scanf("%[^\n]",b);
  printf("%s",b);

The compiler seems to be reading the first read but skips the second read. Why is this happening?

Don't use `scanf`. Use `fgets` and strip of the `\n` if you don't want it — Support Ukraine, Aug 06 '18 at 14:49
Or, if you want to use `scanf`, you can consume and discard the newline with `scanf("%99[^\n]%*c", a);`. (Added `99` to avoid buffer overflow). — 001, Aug 06 '18 at 14:57
Tip: When I/O is not working as expected, the 1st line of defense coding is to **check the result** value of the functions. `int cnt = scanf("%[^\n]",b); if (cnt != 1) printf("Unexpected scan %d\n", cnt);` would have helped this code a lot to narrow the issue. — chux - Reinstate Monica, Aug 06 '18 at 16:06

anoopknr · Answer 1 · 2018-08-06T14:50:57.150

1

Because of un handled Enter Use fgets()

Try this :-

char a[100], b[100], c[100];
fgets(a, 100, stdin);
printf("%s", a);
fgets(b, 100, stdin);
printf("%s", b);

edited Aug 06 '18 at 14:50

answered Aug 06 '18 at 14:48

anoopknr

Why is that a problem? – metasj Aug 06 '18 at 14:50
The `newline` generated in scanning `a` is assigned to `b` – anoopknr Aug 06 '18 at 14:53
1

Testing the return value of `fgets()` would prevent potential undefined behavior on early end of file. – chqrlie Aug 06 '18 at 14:58
@anoopknr [The newline generated in scanning a is assigned to b](https://stackoverflow.com/questions/51710295/reading-multiple-character-arrays-in-c-using-scanf#comment90381945_51710329) --> No. with `scanf("%[^\n]",b);`, `b` would not get a `'\n'` assigned. – chux - Reinstate Monica Aug 06 '18 at 16:08

1 Answers1