PHP array_change_key_case() function

Example

Convert all array keys to uppercase letters:

<?php$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");print_r(array_change_key_case($age,CASE_UPPER));?>

Definition and usage

The array_change_key_case() function converts all keys of an array to uppercase or lowercase letters.

grammar

 array_change_key_case( array , case );

parameter	describe
array	Required. Specifies the array to use.
case	Optional. Possible values: CASE_LOWER - Default value. Convert an array's keys to lowercase letters. CASE_UPPER - Convert array keys to uppercase letters.

technical details

Return value:	Returns an array with keys with lowercase letters, or an array with keys with uppercase letters, or FALSE if array is not an array.
PHP version:	4.2+

More examples

Example 1

Convert all array keys to lowercase letters:

<?php$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");print_r(array_change_key_case($age,CASE_LOWER));?>

Example 2

If after running array_change_key_case() there are two or more keys with the same key (such as "b" and "B"), the last element will overwrite the other elements:

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