Is a switch statement applicable in a factory method? c#

Question

I want to return an Interface and inside a switch statement I would like to set it. Is this a bad design? ``` private IResultEntity GetEntity(char? someType) { IResultEntity entity = null; switch (someType) { case 'L': //life entity = new LifeEntity(); break; case 'P': //property entity = new PropertyEntity(); break; case 'D': //disability entity = new DisabilityEntity(); break; case 'C': //credit card entity = new CreditCardEntity(); break; } return entity; } ```

Accepted Answer

I don't usually mind switch statements in a factory, provided I can group and control all of the derived classes that I want my factory to create in advance.

Sometimes,maybe a user-created plugin might want to add it's own classes to that switch list, and then a swich statement is not enough.

I found this good source for some more info on creating some more powerfull/versatile factory classes

A good middle-ground approach I usually take is to keep a static Dictionary< string,Type > for each factory class.

People can just "register" their own implementations using some sort of

```
Factories.TypeRegistration.StaticDictionary.Add("somekey",typeof(MyDerivedClass))
```

(or better yet, use a Registration method and hide the StaticDictionary)

then the Factory has an easy task of creating an instance by performing a lookup in the table:

```
Activator.CreateInstance(Factories.TypeRegistration.StaticDictionary["somekey"]);
```

Is a switch statement applicable in a factory method? c#

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