array_change_key_case()

array_change_key_case ($input_array , int $size [, bool $preserve_keys = FALSE ] )

Example 1

$input=array('One'=>1,'Two'=>2,'Three'=>3,'Four'=>4,'Five'=>5);
$output=array_change_key_case($input);
echo print_r($output);

Array ( [one] => 1 [two] => 2 [three] => 3 [four] => 4 [five] => 5 ) 1

Example 2 with CASE_UPPER

$input=array('One'=>1,'Two'=>2,'Three'=>3,'Four'=>4,'Five'=>5);
$output=array_change_key_case($input,CASE_UPPER);
echo print_r($output);

Array ( [ONE] => 1 [TWO] => 2 [THREE] => 3 [FOUR] => 4 [FIVE] => 5 ) 1

Example 3 with CASE_LOWER ( default )

$input=array('One'=>1,'Two'=>2,'Three'=>3,'Four'=>4,'Five'=>5);
$output=array_change_key_case($input,CASE_LOWER);
echo print_r($output);

Array ( [one] => 1 [two] => 2 [three] => 3 [four] => 4 [five] => 5 ) 1

Subhendu Mohapatra

Author

🎥 Join me live on YouTube

Passionate about coding and teaching, I publish practical tutorials on PHP, Python, JavaScript, SQL, and web development. My goal is to make learning simple, engaging, and project‑oriented with real examples and source code.

← Subscribe to our YouTube Channel here