getting arrays and replacing spaces with comma - arrays

Question

I'm working on something the whole day and night but it seems like i'm not getting any further with it cause it's a bit complicating for me to learn actually :(
The code is like this:
$aDoor = $_POST['zeilenid'];
if(empty($aDoor))
{
echo("You didn't select anything.");
}
else
{
$N = count($aDoor);
echo("You selected $N entry ID(s): ");
for($i=0; $i < $N; $i++)
{
$str = $aDoor[$i];
$str = ereg_replace(" ",",",$str);
echo($str . " ");
}
}
it doesn't work tho - i want the IDs, which will showing to NOT show them this way: 8 9 10
but rather this way: 8, 9, 10
and save it in ONE variable! how cna i make this happen? What am I doing wrong here?

Answer 1

just try:
$aDoor = $_POST['zeilenid'];
if(empty($aDoor))
{
echo("You didn't select anything.");
}
else
{
$N = count($aDoor);
echo("You selected $N entry ID(s): ");
echo join(", ", $aDoor);
}
join combines all elements of the array into one string and inserts the first parameter between each element
edit: save it:
$str = join(", ", $aDoor);

Answer 2

$clean_search = str_replace(' ', ',', $user_search);
$search_words = explode(' ', $clean_search);
$final_search_words = array();
if (count($search_words) > 0) {
$final_search_words[] = $user_search;
foreach ($search_words as $word) {
if (!empty($word)) {
$final_search_words[] = $word;
}
}
}
This code will replace empty space with comma, and the if condition is used to replace extra spaces with only one space.