Add(123, 456)); echo sprintf("123 + default = %d\r\n", $test->Add(123)); echo sprintf("ABC + XYZ = %s\r\n", $test->Concat("ABC", "XYZ")); echo sprintf("ABC + default = %s\r\n", $test->Concat("ABC")); echo sprintf("IV = %d SV = %s\r\n", $test->IV, $test->SV); $test->IV = 123; $test->SV = "ABC"; echo sprintf("IV = %d SV = %s\r\n", $test->IV, $test->SV); $another = $test->Another(); echo sprintf("Another 123 + 456 = %d\r\n", $another->Add(123, 456)); // second non-default interface is not accessible ?>