problem with scanf

[trail hedge]

my code isnt working as it supposed to and the scanf doesnt seem to end can anyobe hel me ?

[keen nacelle]

When your question is answered use !solved to mark the question as resolved.

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[round jacinth]

Please provide some relevant code

[trail hedge]

!f

[keen nacelle]

!f must be used while replying to a message

[trail hedge]

!f

[keen nacelle]

#include <math.h>
#include <stdio.h>
#include "hw1.h"
#define NUM_QUESTIONS 20

int main(int argc, char* argv[]) {
  int arithmosepilogwn;
  char teleutaiaepilogh;
  char apanthseis[NUM_QUESTIONS];
  char apanthseismath[NUM_STUDENTS][NUM_QUESTIONS];
  double poinh;
  int a = 0;

  do {
    printf("Enter number of choices:\n");
    scanf(" %d", &arithmosepilogwn);
  } while ((arithmosepilogwn > 26) || (arithmosepilogwn < 1));

  teleutaiaepilogh = 'A' + (arithmosepilogwn - 1);
  printf("Max choice: '%c'\n", teleutaiaepilogh);

  printf("Enter answer key:\n");
  char ch;
  for (a = 0; a < NUM_QUESTIONS; a++) {
    int valid = 0;
    do {
      char ch;
      // Read a single character answer from input and ignore spaces
      scanf(" %c",
            &ch);  // The space before %c ensures leading whitespace is skipped

      // Skip spaces
      if (ch == ' ') {
        continue;
      }

      // Validate the character: Must be between 'A' and the last valid choice
      // or '-'
      if ((ch >= 'A' && ch <= teleutaiaepilogh) || ch == '-') {
        apanthseis[a] = ch;  // Store valid answer
        valid = 1;           // Valid answer, break the loop
      } else {
        // If invalid, prompt again
        printf("Error. Enter value A-%c or '-':\n", teleutaiaepilogh);
      }
    } while (!valid);  // Continue until valid input is given
  }

Periandross

[high ember]

Whats wrong with scanf?

You have scanf accepting a int/number, if the user types in a letter. It will segfault. Use fgets() !

Same with the other scanf()s

[gusty spindle]

it won't segfault. no. it'll just return without parsing it

[gusty spindle]

it seems you redeclared ch in the inner block of that loop for some reason, please remove one of those declarations. other than that - i can't see what the problem seems to be. can you elaborate on what exactly 'isn't working'?

[pulsar owl]

;compile -fanalyzer

[tawdry sonnet]

Compiler Output

<source>:3:10: fatal error: hw1.h: No such file or directory
    3 | #include "hw1.h"
      |          ^~~~~~~
compilation terminated.
Build failed

mage7717 | c++ | x86-64 gcc 14.2 | godbolt.org

[pulsar owl]

scanf() blocks (that is, it stops your code and waits) until it has some data to work with, and stdin (the place scanf() reads from) doesnt contain anything until it receives a \n character

[gusty spindle]

eh... not quite. stdin by default is indeed line buffered, but you can change it with setvbuf. in addition the terminal you're using is likely line buffered too, however that can be changed as well

[trail hedge]

!solved

[keen nacelle]

Thank you and let us know if you have any more questions!

This thread is now set to auto-hide after an hour of inactivity

[high ember]

Really