?<?php
//抽象類 定義屬性及抽象方法
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();
}

//操作類
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;
    }
}
…………

//工廠類
class OperationFactory{
    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;
            ……
        }
    }
}

//操作
$obj = OperationFactory:: CreationOperation('+',5,6);
echo $obj-> getResult();
?>