PHP array_change_key_case() Function

Example 1

<?php
$a=array("a"=>"Cat","b"=>"Dog","c"=>"Horse");
print_r(array_change_key_case($a,CASE_UPPER));
?>

Example 2

<?php
$a=array("a"=>"Cat","b"=>"Dog","c"=>"Horse","B"=>" Bird");
print_r(array_change_key_case($a,CASE_UPPER));
?>