C program to delete vowels from a string

Remove vowels from a string in c: c program to remove or delete vowels from a string, if the input string is "c programming" then output will be "c prgrmmng". In the program we create a new string and process entered string character by character, and if a vowel is found it is not added to new string otherwise the character is added to new string, after the string ends we copy the new string into original string. Finally we obtain a string without any vowels.

C programming code

#include <stdio.h>
#include <string.h>
 
int check_vowel(char);
 
int main()
{
  char s[100], t[100];
  int i, j = 0;
 
  printf("Enter a string to delete vowels\n");
  gets(s);
 
  for(i = 0; s[i] != '\0'; i++) {
    if(check_vowel(s[i]) == 0) {       //not a vowel
      t[j] = s[i];
      j++;
    }
  }
 
  t[j] = '\0';
 
  strcpy(s, t);    //We are changing initial string
 
  printf("String after deleting vowels: %s\n", s);
 
  return 0;
}
 
 
int check_vowel(char c)
{
  switch(c) {
    case 'a':
    case 'A':
    case 'e':
    case 'E':
    case 'i':
    case 'I':
    case 'o':
    case 'O':
    case 'u':
    case 'U':
      return 1;
    default:
      return 0;
  }
}

Output of program:

C programming code using pointers

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define TRUE 1
#define FALSE 0
 
int check_vowel(char);
 
main()
{
   char string[100], *temp, *pointer, ch, *start;
 
   printf("Enter a string\n");
   gets(string);
 
   temp = string;
   pointer = (char*)malloc(100);
 
  if( pointer == NULL )
   {
      printf("Unable to allocate memory.\n");
      exit(EXIT_FAILURE);
   }
 
   start = pointer;
 
   while(*temp)
   {
      ch = *temp;
 
      if ( !check_vowel(ch) )
      {
         *pointer = ch;
         pointer++;
      }
      temp++;
   }
   *pointer = '\0';
 
   pointer = start;
   strcpy(string, pointer); /* If you wish to convert original string */
   free(pointer);
 
   printf("String after removing vowel is \"%s\"\n", string);
 
   return 0;
}
 
int check_vowel(char a)
{
   if ( a >= 'A' && a <= 'Z' )
      a = a + 'a' - 'A';
 
   if ( a == 'a' || a == 'e' || a == 'i' || a == 'o' || a == 'u')
      return TRUE;
 
   return FALSE;
}