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PHP array_change_key_case() Function

❮ PHP Array Reference

Example

Change all keys in an array to uppercase:

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

Definition and Usage

The array_change_key_case() function changes all keys in an array to lowercase or uppercase.


Syntax

array_change_key_case(array, case)
Parameter Description
array Required. Specifies the array to use
case Optional. Possible values:
  • CASE_LOWER - Default value. Changes the keys to lowercase
  • CASE_UPPER - Changes the keys to uppercase

Technical Details

Return Value: Returns an array with its keys in lowercase or uppercase, or FALSE if array is not an array
PHP Version: 4.2+


More Examples

Example

Change all keys in an array to lowercase:

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

Example

If two or more keys will be equal after running array_change_key_case() (e.g. "b" and "B"), the latest array will override the other:

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

❮ PHP Array Reference