Supported Versions: PHP 5, PHP 7, PHP 8
Case-insensitive version of str_replace()
<?php str_ireplace(    array|string $search,    array|string $replace,    string|array $subject,    int &$count = null): string|array
<?php         return $caseSensitive

                ? str_replace($search, $replace, $subject)

                : str_ireplace($search, $replace, $subject);

    }
<?php         return $caseSensitive

                    ? str_replace($search, '', $subject)

                    : str_ireplace($search, '', $subject);

    }
<?php         foreach ($segments as $segment) {

            if (is_numeric($segment)) {

                if ($numericIndex === 1) {

                    $message = str_ireplace(':'.$placeholder, $modifier((int) $segment), $message);

                }



                $message = str_ireplace(
<?php                     $message = str_ireplace(':'.$placeholder, $modifier((int) $segment), $message);

                }



                $message = str_ireplace(

                    ':'.$this->numberToIndexOrPositionWord($numericIndex).'-'.$placeholder,

                    $modifier((int) $segment),

                    $message

                );



                $numericIndex++;

            }