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PHP array_change_key_case() Function

PHP Array Reference Complete PHP Array Reference

Definition and Usage

The array_change_key_case() function returns an array with all array KEYS in lower case or upper case.

Syntax

array_change_key_case(array,case)

Parameter Description
array Required. Specifies the array to use
case Optional. Possible values:
  • CASE_LOWER - Default value. Returns the array key values in lower case.
  • CASE_UPPER - Returns the array key values in upper case.

Tips and Notes

Note: If two or more array keys will be the same after running this function, the last array will override the others. (See example 2)

Example 1

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

The output of the code above will be:

Array ( [A] => Cat [B] => Dog [C] => Horse )

Example 2

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

The output of the code above will be:

Array ( [A] => Cat [B] => Bird [C] => Horse )

PHP Array Reference Complete PHP Array Reference
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