vars[$name] = $var; } public function getVariable($name) { return $this->vars[$name]; } } $test = new my_abc; $test->setVariable('foo','bar'); echo $test->getVariable('foo'); ?>]]> Now, how about if we don't implement the interface correctly: test = 'something'; } } ?>]]> Fatal error: Class my_other_class contains 2 abstract methods and must therefore be declared abstract (abc::setVariable, abc::getVariable) in script.php on line 2