<?php
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 clearResult(){
$this->_Result = 0;
}
abstract protected function getResult();
}
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 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;
}
return self::$obj;
}
}
$obj = OperationFactory::CreateOperation(‘-‘, 5, 6);
echo $obj->getResult();
simple -- abstract
原文：http://www.cnblogs.com/yhdsir/p/4649192.html
