Create a comma-separated string from a single column of an array of objects

$result_names = '';
foreach($results as $result){
    $result_names .= $result->name.',';
}
echo rtrim($result_names, ',');

1. Concat to string but add | before

$s = '';
foreach ($results as $result) { 
    if ($s) $s .= '|';
    $s .= $result->name; 
}
echo $s;

2. Echo | only if not last item

$s = '';
$n = count($results);
foreach ($results as $i => $result) { 
    $s .= $result->name;
    if (($i+1) != $n) $s .= '|';
}
echo $s;

3. Load to array and then implode

$s = array();
foreach ($results as $result) { 
    $s[] = $result->name;
}
echo implode('|', $s);

4. Concat to string then cut last | (or rtrim it)

$s = '';
foreach ($results as $result) { 
    $s .= $result->name . '|';
}
echo substr($s, 0, -1); # or # echo rtrim($s, '|');

5. Concat string using array_map()

echo implode('|', array_map(function($result) { return $result->name; }, $results));

Better:

$resultstr = array();
foreach ($results as $result) {
  $resultstr[] = $result->name;
}
echo implode(",",$resultstr);