Three categories summarize five PHP design patterns

Three categories summarize five PHP design patterns

Factory model Single element mode Observer Mode Command chain mode Rule mode Class people { Private $ name = ''; Private $ user = null; Private function _ constract ($ name) {/* Here private defines the mode to assist in implementing a single element */ $ This-> name = $ name; } Public static function instance ($ name) {/* This method implements the factory mode */ Static $ object = null;/* This variable implements the single-element mode */ If (is_null ($ object )) $ Object = new people ($ name ); Return $ object; } Public function work_in ($ who = null) { If (is_null ($ who) echo 'error '; Else { $ This-> user [] = $ who;/* this array variable implements the observer mode */ Echo $ who-> work ();/* Implementation policy mode of this method call */ } } Public function on_action ($ which = ''){ If (empty ($ which) echo 'error '; Else { Foreach ($ this-> user as $ user) $ User-> action ($ which);/* call this method to implement the command chain mode */ } } } $ People = people: instance ('Jack '); $ People-> work_in (new student ); $ People-> work_in (new teacher ); $ People-> on_action ('eat '); Class student { Function work (){ Echo' I am a student, 9 to 5. '; } Function action ($ which ){ If (method_exists ($ this, $ which) return $ this-> $ which (); Else echo 'you are wrong! '; } Function eat (){ Echo' I am a student and can only eat a package. '; } } Class teacher { Function work (){ Echo' I am a teacher and have the busiest time preparing lessons at night. '; } Function action ($ which ){ If (method_exists ($ this, $ which) return $ this-> $ which (); Else echo 'I can not do it! '; } Function eat (){ Echo' I am a teacher and can have a big meal every day. '; } }