<?php class calc { function plus($a, $b) { return $a + $b; } function minus($a, $b) { return $a - $b; } } $calc = new calc(); echo $calc->plus('2', '2').' and '.$calc->minus('4', '2'); ?> <html> <head> <title>Hello World!</title> </head> <body> <h1>Hello World!</h1> </body> <hrml>