换成工厂方法模式

    2. {
    3.     public function CreateOperation();
    4. }
    6. class AddFactory implements IFactory
    7. {
    8.     public function CreateOperation()
    9.     {
    10.         return new OperationAdd();
    11.     }
    12. }
    15.     public function CreateOperation()
    16.     {
    17.         return new OperationSub();
    18.     }
    19. }
    21. class MulFactory implements IFactory
    22. {
    23.     public function CreateOperation()
    24.     {
    25.         return new OperationMul();
    26.     }
    28. class DivFactory implements IFactory
    29. {
    30.     public function CreateOperation()
    31.     {
    32.         return new OperationDiv();
    33.     }
    34. }
    36. //客户端代码
    37. $operationFactory = new AddFactory();
    38. $operation = $operationFactory->CreateOperation();
    39. $operation->setA(10);

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