Why isn't my array working?

[HelloJarvis]

Hi guys,

I'm working on a little script that generates all combinations of a given input string. My problem is, it's generating the combinations perfectly fine (I checked with an echo), but not inserting them in to an array. Here is my code:

function check($width, $position, $base_string, $charSet)
{
    $combinations = array();    

    for ($i = 0; $i < strlen($charSet); $i++) 
    {
        if ($position  < $width - 1) 
            check($width, $position + 1, $base_string . $charSet[$i], $charSet);            

        $combinations[] = $base_string . $charSet[$i];
        //echo statement here for debugging
    }

    return $combinations;
}

$word = "hello"

$combinations = array_unique(check(strlen($word), 0, "", $word));

foreach ($combinations as $value)
    echo $value;

For some reason, if I add an echo statement to where I marked it in the comment, it prints the values fine. For some reason, it's not inserting them in to the array.

[urtrivedi]

what you return you are not passing back to calling function

if ($position  < $width - 1) 
            check($width, $position + 1, $base_string . $charSet[$i], $charSet); 

You must store output of check(...)function to some array, so you are looing your processsed output here.

         if ($position  < $width - 1) 
            $retcomb=check($width, $position + 1, $base_string . $charSet[$i], $charSet); 

[Bachu]

Check this

function check($width, $position, $base_string, $charSet,$combinations)
{
    for ($i = 0; $i < strlen($charSet); $i++) 
    {
        if ($position  < $width - 1) 
         $combinations .= check($width, $position + 1, $base_string.$charSet[$i], $charSet, $combinations);            

       $combinations .= $base_string . $charSet[$i].'-';
    }

        return $combinations;
}

$word = "Hel";

$combinations = check(strlen($word), 0, "", $word, '');
$values = array_unique(explode("-", $combinations));

foreach ($values as $value)
    echo $value.'<br />';