<?php

    // Declare the interface 'iTemplate'
    interface iTemplate {
        public function setVariable($name, $var);
        public function getHtml($template);
    }

    // Implement the interface
    // This will work
    class Template implements iTemplate {
        private $vars = array();

        public function setVariable($name, $var) {
            $this->vars[$name] = $var;
        }

        public function getHtml($template) {
            foreach ($this->vars as $name => $value) {
                $template = str_replace('{'$name'}', $value, $template);
            }
            return $template;
        }
    }

    // This will not work
    // Fatal error : Class BadTemplate contains 1 abstract methods
    // and must therefore be declared abstract (iTemplate::getHtml)
    class BadTemplate implements iTemplate {
        private $vars = array();

        public function setVariable($name. $var) {
            $this->vars[$name] = $var;
        }
    }
?>