clean array of blanks, array subscripting

I've been trying to understand why I'm getting wrong output with this function. It must be somewhere where I count the chars in the array.
Here it goes.

Code:

int clean_array(char array[], char clean[], int size)
{
    int i, j = 0;

/* j is to count index of the array cleaned out of      */
/*blanks and punct marks. i is for the original array */ 

    for(i = 0; i < size; i++)
    {
       if( isalpha(array[i]) )
       {                                 /* if char is a letter, put it in the */
          clean[j] = array[i];   /* other array. Increment its index */
          j++;                
       }                      
    }
 
    clean[j] = '\0';      /* as index is incremented already, just */     
                                /* close the string */
 
    return (j-1);         /* return the number of chars in string */       
}

So, when I input a random choice of chars, e.g
jhy ut!
and store it in the original array, the program cleans it up correctly and my result is (using puts):
jhyutP
The last letter I believe is something random, maybe from outside of the clean string.
What did I do wrong with the subscripting?

Can you post the context of the call?

Code:

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

int clean_array(char array[], char clean[], int size)
{
    int i, j = 0;
    for(i = 0; i < size; i++)
    {
       if( isalpha(array[i]) )
       {
          clean[j++] = array[i];
       }                      
    }
    clean[j] = '\0';
    return (j-1);
}

int main( void )
{
   char original[] = "abc 123 QRS !@# xyz";
   char result [ sizeof original ];
   puts(original);
   clean_array(original, result, sizeof original);
   puts(result);
   return 0;
}

/* my output
abc 123 QRS !@# xyz
abcQRSxyz
*/

>>return (j-1);
This is wrong. You need to return j, not j-1. Most likely the problem your having is that you are passing a size to clean_array that is one too much.

Whether it returns j or j-1, the result is exactly the same...
And the call for this function is this:

Code:

clean_number = clean_array(message, clean_message, LEN);

I'm have no idea what is going on. Watever change I have made so far with indexing, the result is the same...

What is LEN defined as?

#define LEN 40

How hard is this to figure out, really? Dave already showed you that the function itself works as expected. Therefore, you're either:
a) Using it incorrectly.
b) Declaring your variables incorrectly.
c) Doing something else stupid.
d) All of the above.

The function works, your use of it is wrong. Now figure out why. It's allready been demonstrated that the function itself gives the expected output. Therefore, it is not the problem.

Quzah.