Build comma separated string in PHP Loop

Question

Hello Guys i need to do this,

I have a common loop

foreach ($stuffs as $stuff) {
echo $stuff;
}

Lets assume $stuff is an \'id\' of a my

Answer 1

This worked in my case (detects if isn't the loop last iteration):

foreach($array as $key => $val){
    ...
    if($key!==count($array)-1){echo ',';}
}