(PHP 4 >= 4.2.0, PHP 5, PHP 7)
array_change_key_case — Changes the case of all keys in an array
$array
[, int $case = CASE_LOWER
] )
Returns an array with all keys from array lowercased
or uppercased. Numbered indices are left as is.
arrayThe array to work on
case
Either CASE_UPPER or
CASE_LOWER (default)
Returns an array with its keys lower or uppercased, or FALSE if
array is not an array.
Throws E_WARNING if array is
not an array.
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
)
Note:
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.