app/I18N.php
public static function strcasecmp($string1, $string2): int
    {
        if (self::$collator instanceof Collator) {
            return self::$collator->compare($string1, $string2);
        }

        return strcmp(self::strtolower($string1), self::strtolower($string2));
    }
public static function strcasecmp($string1, $string2): int
    {
        if (self::$collator instanceof Collator) {
            return self::$collator->compare($string1, $string2);
        }

        return strcmp(self::strtolower($string1), self::strtolower($string2));
    }
public static function strcasecmp ( $ string1 , $ string2 ) : int { if ( self :: $ collator instanceof Collator ) { return self :: $ collator -> compare ( $ string1 , $ string2 ) ; } return strcmp ( self :: strtolower ( $ string1 ) , self :: strtolower ( $ string2 ) ) ; }
Perform a case-insensitive comparison of two strings.

@param string $string1
@param string $string2

@return int
Perform a case - insensitive comparison of two strings .