Detailed introduction to factory pattern based on PHP design pattern

Detailed introduction to factory pattern based on PHP design pattern_PHP tutorial

WBOY

Release： 2016-07-21 15:10:11

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Factory pattern: The factory class determines which instance of the production class to create based on the parameters
Factory class: A method class specifically used to create other objects. That is, allocate on demand, pass in parameters for selection, and return the specific class
Function: encapsulation of object creation, simplifying the operation of creating objects, that is, calling a method of the factory class to get the required class
Supplement:
1. Main roles: Abstract Product (Product), Concrete Product (Concrete Product), Abstract Factory Role (Creator)
2. Advantages and Disadvantages
Advantages: The factory method pattern allows the system to introduce new products without modifying the factory role
Disadvantages: Customers may have to create a Creator subclass just to create a specific Concrete Product object
3. Applicability
When a class does not know the objects it must create
When a class wants its subclasses to specify the objects it creates
When a class delegates the responsibility for object creation to one of multiple helper subclasses and wants you to localize the information about which helper subclass is the delegate

Copy Code The code is as follows:

//Object
class MyObject{
public function __construct(){}
public function test(){
return 'test'; ;
}
}

$myObject = MyFactory::factory();
echo $myObject->test();
?>

?//Abstract class definition attributes and abstract methods
abstract class Operation{
protected $_NumberA = 0;
protected $_NumberB = 0;

protected $ _Result= 0;

public function __construct($A,$B){
$this->_NumberA = $A;
$this->_NumberB = $B;
}

public function setNumber($A,$B){
$this->_NumberA = $A;
$this->_NumberB = $B;
}

public function clearResult(){
$this->_Result = 0;
}

abstract protected function getResult();
}

/ /Operation class
class OperationAdd extends Operation{
public function getResult(){
$this->_Result = $this->_NumbserA + $this->_NumberB;
return $this ->_Result;
}
}

class OperationSub extends Operation{
public function getResult(){
$this->_Result = $this->_NumberA - $this->_NumberB;
return $this->_Result; 🎜> private static $obj;

public static function CreationOperation($type,$A,$B){
switch($type){
case '+':
self: :$obj = new OperationAdd($A,$B);
break;
case '-':
self::$obj = new OperationSub($A,$B);
break ;
… … echo $obj-> getResult();
?>