Assigning character to a character variable in a nested loop does not work in c

Question

I'm making a code to generate a random rank for a college assignment. And the program looks like this:

#include <conio.h>
#include <ctype.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

char rankgen()
{
  char rank;
  int randnum = (rand() % 13) + 1;
  // printf("randnum: %d\n", randnum);

  if (randnum != 1 || randnum != 11 || randnum != 12 || randnum != 13
      || randnum != 10) {
    rank = randnum + '0';
  } else {
    if (randnum == 10)
      rank = 1 + '0';
    else if (randnum == 1)
      rank = 'A';
    else if (randnum == 11)
      rank = 'J';
    else if (randnum == 12)
      rank = 'Q';
    else if (randnum == 13)
      rank = 'K';
  }
  return rank;
}

char rankgen2()
{
  char rank;
  int randnum = (rand() % 13) + 1;
  // printf("randnum: %d\n", randnum);

  if (randnum != 1 || randnum != 11 || randnum != 12 || randnum != 13
      || randnum != 10) {
    rank = randnum + '0';
  }
  if (randnum == 10)
    rank = 1 + '0';
  if (randnum == 1)
    rank = 'A';
  if (randnum == 11)
    rank = 'J';
  if (randnum == 12)
    rank = 'Q';
  if (randnum == 13)
    rank = 'K';
  return rank;
}

int main()
{
  srand(time(NULL));
  for (int i = 0; i < 30; i++) {
    char rank = rankgen();
    char rank2 = rankgen2();
    printf("%c, %c\n", rank, rank2);
  }
  return 0;
}

It seems like I can't assign a char into a char variable when using a nested loop or in an if-else statement. I could temporarily fix that by making it not inside any of the loop or any statement. It would help a lot if you explain why does it happen and how to fix it.

Answer 1

You only need one rankgen function (since they both do exactly the same thing), and it should look something like this:

char rankgen()
{
    char rank;
    int randnum = (rand() % 13) + 1;

    if (randnum == 1)
        rank = 'A';
    else if (randnum == 10)
        rank = 'T';
    else if (randnum == 11)
        rank = 'J';
    else if (randnum == 12)
        rank = 'Q';
    else if (randnum == 13)
        rank = 'K';
    else
        rank = randnum + '0';
    return rank;
}

Note that as @EugeneSh pointed out, the initial if statement is wrong; since no value can be equal to more than one different value, it will always be false. Because of this, most of the time you return a garbage value in rank. Also, I'm not sure what you meant for your == 10 case to do, but I changed it to make the character 'T' (for "Ten").

You could also do this with a switch statement like this:

char rankgen()
{
    char rank;
    int randnum = (rand() % 13) + 1;

    switch (randnum) {
        case 1:
            rank = 'A';
            break;
        case 10:
            rank = 'T';
            break;
        case 11:
            rank = 'J';
            break;
        case 12:
            rank = 'Q';
            break;
        case 13:
            rank = 'K';
            break;
        default:
            rank = randnum + '0';
            break;
    }
    return rank;
}

Answer 2

For example this if statement

  if (randnum != 1 || randnum != 11 || randnum != 12 || randnum != 13
      || randnum != 10) {
    rank = randnum + '0';
  } else {
    if (randnum == 10)
      rank = 1 + '0';
    else if (randnum == 1)
      rank = 'A';
    else if (randnum == 11)
      rank = 'J';
    else if (randnum == 12)
      rank = 'Q';
    else if (randnum == 13)
      rank = 'K';
  }

does not make a sense.

It is unimportant what value is stored in the variable randnum the first if statement in any case

  if (randnum != 1 || randnum != 11 || randnum != 12 || randnum != 13
      || randnum != 10) {
    rank = randnum + '0';

will get the control.

It seems you mean

  if (randnum != 1 && randnum != 11 && randnum != 12 && randnum != 13
      && randnum != 10) {

Also there is no great sense to define two functions that are identical.