How can developers ensure that their PHP scripts handle case sensitivity appropriately when performing string replacements?

Developers can ensure that their PHP scripts handle case sensitivity appropriately when performing string replacements by using the case-insensitive version of functions like `str_replace()` or `preg_replace()`. This ensures that the replacements are done regardless of the case of the strings being searched for. Another approach is to use functions like `str_ireplace()` which specifically handle case-insensitive replacements.

// Using str_ireplace() for case-insensitive string replacements
$string = "Hello World";
$newString = str_ireplace("hello", "Hi", $string);
echo $newString; // Output: Hi World