- array_search: documentation ( source)
- max: documentation ( source)
- array_walk: documentation ( source)
<?php
$array = array(
'Google',
'Facebook',
'Twitters',
'Slack',
'Twilio',
);
$r = null;
array_walk($array, function($v, $k) use (&$r){
$r[$v] = strlen($v);
});
echo array_search(max($r), $r);