- array_map: documentation ( source)
- implode: documentation ( source)
<?php
$input = array(
array(
'tag_name' => 'google',
'dsddsdsd'=>'dsdsdsd'
),
array(
'tag_name' => 'technology',
'wqwqw'=>'qwwqw'
)
);
echo implode(', ', array_map(function ($entry) {
return $entry['tag_name'];
}, $input));