<?php
/* 示例2： */
//简单工厂模式
/*
* 定义运算类
*/
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;
}
/* protected function clearResult(){
$this->_Result = 0;
} */
public function clearResult(){
return $this->_Result = 0;
}
//抽象方法无方法体
abstract protected function getResult();
}
//继承一个抽象类的时候，子类必须实现抽象类中的所有抽象方法；
//另外，这些方法的可见性 必须和抽象类中一样（或者更为宽松）
class OperationAdd extends Operation {
public function getResult(){
$this->_Result=$this->_NumberA + $this->_NumberB;
return $this->_Result;
}
}
class OperationSub extends Operation {
public function getResult(){
$this->_Result=$this->_NumberA - $this->_NumberB;
return $this->_Result;
}
}
class OperationMul extends Operation {
public function getResult(){
$this->_Result=$this->_NumberA * $this->_NumberB;
return $this->_Result;
}
}
class OperationDiv extends Operation {
public function getResult(){
$this->_Result=$this->_NumberA / $this->_NumberB;
return $this->_Result;
}
}
class OperationFactory {
//创建保存实例的静态成员变量
private static $obj;
//创建访问实例的公共的静态方法
public static function CreateOperation($type,$A,$B){
switch($type){
case '+':
self::$obj = new OperationAdd($A,$B);
break;
case '-':
self::$obj = new OperationSub($A,$B);
break;
case '*':
self::$obj = new OperationMul($A,$B);
break;
case '/':
self::$obj = new OperationDiv($A,$B);
break;
}
return self::$obj;
}
}
/*
$obj = OperationFactory::CreateOperation('+');
$obj->setNumber(4,4);
*/
$obj = OperationFactory::CreateOperation('*',5,6);
echo $obj->getResult(); //30
echo "<br/>";
echo $obj->clearResult(); //0
echo '<br>';
/* echo $obj->_Result; */
