Is it possible to make str_replace in PHP case-insensitive when removing characters?

When using the `str_replace` function in PHP to remove characters from a string, it is case-sensitive by default. To make it case-insensitive, you can use a combination of `str_ireplace` and `strtolower` functions. By converting both the search string and the subject string to lowercase, you can ensure that the replacement is done in a case-insensitive manner.

$string = "Hello World";
$charactersToRemove = "o";
$result = str_ireplace(strtolower($charactersToRemove), "", strtolower($string));
echo $result; // Output: Hell Wrld