app/I18N.php
public static function strtoupper($string): string
    {
        if (in_array(self::$locale->language()->code(), self::DOTLESS_I_LOCALES, true)) {
            $string = strtr($string, self::DOTLESS_I_TOUPPER);
        }

        return mb_strtoupper($string);
    }
public static function strtoupper($string): string
    {
        if (in_array(self::$locale->language()->code(), self::DOTLESS_I_LOCALES, true)) {
            $string = strtr($string, self::DOTLESS_I_TOUPPER);
        }

        return mb_strtoupper($string);
    }
public static function strtoupper ( $ string ) : string { if ( in_array ( self :: $ locale -> language ( ) -> code ( ) , self :: DOTLESS_I_LOCALES , true ) ) { $ string = strtr ( $ string , self :: DOTLESS_I_TOUPPER ) ; } return mb_strtoupper ( $ string ) ; }
Convert a string to upper case.

@param string $string

@return string
Convert a string to upper case .