selecting an array key based on partial string
you would have to iterate over your array to check each key separately, since you don't have the possibility to query the array directly (I'm assuming the array also holds totally unrelated keys, but you can skip the if part if that's not the case):
foreach($array as $k => $v){ if (strpos($k, 'show_me_') !== false) { $number = substr($k, strrpos($k, '_')); }}However, this sounds like a very strange way of storing data, and if I were you, I'd check if there's not an other way (more efficient) of passing data around in your application ;)