Three classes summarize PHP's five design patterns _php instance

Factory mode
Single element mode
Observer mode
Command chain mode
Policy mode

Copy Code code as follows:

class People {
Private $name = ';
Private $user = null;
Private Function __constract ($name) {//* Here Private defines the auxiliary implementation single element mode * *
$this->name = $name;
}
public static function instance ($name) {* * This method implements Factory mode * *
Static $object = null;/* This variable to implement a single element mode * *
if (Is_null ($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 $who->work ()/* This method invokes the implementation policy mode.
}
}
Public Function on_action ($which = ' ") {
if (empty ($which)) echo ' ERROR ';
else {
foreach ($this->user as $user)
$user->action ($which);/* This method calls the implementation of the command chain mode * *
}
}
}
$people = people::instance (' Jack ');
$people->work_in (new student);
$people->work_in (new teacher);
$people->on_action (' eat ');
Class Student {
function work () {
Echo ' <br/> I am a student, facing nine to five. ';
}
function Action ($which) {
if (Method_exists ($this, $which)) return $this-> $which ();
else echo ' you are wrong! ';
}
Function Eat () {
Echo ' <br/> I am a student, can only eat the package. ';
}
}
Class Teacher {
function work () {
Echo ' <br/> I'm a teacher and I'm busy preparing for the evening. ';
}
function Action ($which) {
if (Method_exists ($this, $which)) return $this-> $which ();
else echo ' I can don't do it! ';
}
Function Eat () {
Echo ' <br/> I am a teacher, can eat a big meal every day. ';
}
}