Question

This is a very small question, and probably something really silly! But why am I getting garbage returned in my output for this function which should remove double letters?

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

char  *makehello( char *s ) {
   char new[16] ;
   int i ;
   int c = strlen(s);
   for ( i = 0; i < (c + 1); i++)
     if (toupper(s[i]) != toupper(s[i+1]))
       new[i] = toupper(s[i]);
return strdup( new ) ;  
}

int main(void) {
 char *new;
 char data[100];
 scanf("%s", data);
 new = makehello(data);
 printf("%s", new);
return 0;
}

Answer 1

You need a separate count for your ‘new’ array. You’re storing them at index ‘i’ (where you found the character), but what you really want is to store them from position 0 and increment this count instead.

EDIT: Of course this isn’t a fullproof method.

i.e something like this:

   for ( i = 0; i < c; i++)
   {
        if (toupper(s[i]) != toupper(s[i+1]))
        {
            new[count++]= toupper(s[i]);
        }
   }
   new[count] = '\0';