Description
array 
array_change_key_case ( array input [, int case] )
     array_change_key_case() changes the
     keys in the input array to
     be all lowercase or uppercase. The change depends
     on the last optional case
     parameter. You can pass two constants there,
     CASE_UPPER and
     CASE_LOWER. The default is
     CASE_LOWER. The function will leave
     number indices as is.
    
| Example 1. array_change_key_case() example | 
<?php$input_array = array("FirSt" => 1, "SecOnd" => 4);
 print_r(array_change_key_case($input_array, CASE_UPPER));
 ?>
 | 
 The above example will output: | Array
(
    [FIRST] => 1
    [SECOND] => 4
) | 
 | 
     If an array has indices that will be the same once run through this
     function (e.g. "keY" and "kEY"), the value that is later in the array
     will override other indices.