php function array_key_exists and regular expressions

Question

Is it possible to use a regular expression with the php function array_key_exists()?

For example:

$exp = "my regex";   array_key_exists($exp, $array); 

Thank you!

Answer 1

You can extract the array keys using array_keys() and then use preg_grep() on that array:

function preg_array_key_exists($pattern, $array) {     $keys = array_keys($array);         return (int) preg_grep($pattern,$keys); } 

.

$arr = array("abc"=>12,"dec"=>34,"fgh"=>56);  var_dump(preg_array_key_exists('/c$/',$arr)); // check if a key ends in 'c'. var_dump(preg_array_key_exists('/x$/',$arr)); // check if a key ends in 'x'.  function preg_array_key_exists($pattern, $array) {     // extract the keys.     $keys = array_keys($array);          // convert the preg_grep() returned array to int..and return.     // the ret value of preg_grep() will be an array of values     // that match the pattern.     return (int) preg_grep($pattern,$keys); } 

Output:

$php a.php int(1) int(0) 

Answer 2

No, I'm afraid not. You can iterate the array keys and perform matches on those:

$keys = array_keys($array); foreach ($keys as $key)   if (preg_match($exp, $key) == 1)     return $array[$key];