I have some doubts regarding my if condition-CodePudding

I'm just a noob/newbie in the C/programming world. I'll first post the code and then I'll describe my problem.

#include <stdio.h>
#include <string.h>

int
main ()
{
  char f[30], j[30] = "mount everest";
  int s,a=0;
  printf ("\n");
  printf ("2) Which is the tallest mountain in the world?\n");
  printf ("\n");
  printf ("Please type your answer below\n");
  scanf("%[a-z]s",f);
  s = strcmp (f, j);
  printf ("\n");
 
  if (s == 0)
    {
      printf ("Congratulations! You have recieved a point!\n");
      a  ;
    }
  else
    {
      printf ("Sorry! Better luck next time!");
      a--;
    }
  
  return 0;
}

So when I try to type the answer as "mount everest", the output goes directly to my 'else'(Sorry! Better luck next time!) statement. Also, I want the program to only accept small letters(as I've defined it a strict rule to be followed throughout the quiz).

**OUTPUT** 

2) Which is the tallest mountain in the world?

Please type your answer below
mount everest

Sorry! Better luck next time!

But when I use (not)'!s' instead of 's' in my if condition, it fulfills the if condition and prints the message as 'Congratulations! You have recieved a point!'. I really don't know what is going on? I had the same approach for my other 2 questions and they all worked perfectly without this '!' issue.

#include <stdio.h>
#include <string.h>

int
main ()
{
  char f[30], j[30] = "mount everest";
  int s,a=0;
  printf ("\n");
  printf ("2) Which is the tallest mountain in the world?\n");
  printf ("\n");
  printf ("Please type your answer below\n");
  scanf("%[a-z]s",f);
  s = strcmp (f, j);
  printf ("\n");
 
  if (!s == 0)
    {
      printf ("Congratulations! You have recieved a point!\n");
      a  ;
    }
  else
    {
      printf ("Sorry! Better luck next time!");
      a--;
    }
  
  return 0;
}

**OUTPUT**

2) Which is the tallest mountain in the world?

Please type your answer below
mount everest

Congratulations! You have recieved a point!

So someone can please explain this to me of what is happening(as I'm new so I kinda don't know how to understand debugging) and what am I doing wrong here? Also, if you cannot understand from this section of the code, I'll post the whole code here but for now I thought it would be too overwhelming so if u want then pleasedo let me know! Thank you for taking the time to go through my problem. Any help is very much appreciated.

EDIT

I programmed the code again with the help of such useful comment from you guys/contributers(thank u all for taking the time to help this newbie) now I'll show you the revised/new code first:

#include <stdio.h>
#include <string.h>

int
main ()
{
  char f[30], j[30] = "mount everest";
  int s,a=0;
  printf ("\n");
  printf ("2) Which is the tallest mountain in the world?\n");
  printf ("\n");
  printf ("Please type your answer below\n");
  fgets(f,15,stdin);
  printf("%s\n",f);
  printf("%s\n",j);
  printf ("\n");
  s=strcmp(f,j);
  if (s==0)
    {
      printf ("Congratulations! You have recieved a point!\n");
      a  ;
    }
  else
    {
      printf ("Sorry! Better luck next time!");
      a--;
    }
    
  
  return 0;
}

But now I'm again being thrown back at the else condition. Like this:

Output

2) Which is the tallest mountain in the world?

Please type your answer below
mount everest
mount everest

mount everest

Sorry! Better luck next time!

I know there is an issue with the 'if' condition but can't seem to figure out what it is. So if anyone can detect my error then I would be really glad. Once again thank you all for helping me.

CodePudding user response：

The reason why your program is not working is because your scanf is not taking the whole line as input. Instead, it is taking the first word. Try to use scanf("%[^\n]%*c",f);

In future when your code is not working, try to print and verify the input you're receiving and validate from it.

CodePudding user response：

scanf("%[a-z]s",f);

should be

scanf("%[a-z ]",f);

%[a-z] means look for a nonempty sequence of lower case characters. You forgot to tell it to look for space.

Also %[a-z]s means look for a nonempty sequence of lower case characters followed by an 's'.