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How to avoid getters and setters

Asked 2012-02-23T15:40:46.340
30

I have read in many places that "getters and setters are evil". And I understood why so. But I don't know how to avoid them completely. Say Item is a class that has information about item name, qty, price etc... and ItemList is a class, which has a list of Items. To find the grand total: 

int grandTotal()
{
int total = 0;

for (Item item: itemList)
       total += item.getPrice();

return total;
}

In the above case, how does one avoid getPrice()? The Item class provides getName, setName, etc....

How do I avoid them?

oop design-patterns properties ooad accessor
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21

It's a shame to see a small, vocal minority take a back lash against the whole "Getters and Setters" are evil debate. Firstly the article title is purposely provocative to draw you in, as should any blog post. I've in turn blogged about this before and several years later updated my opinions and ideas about this question. I'll summarise the best I can here.

  • Getters and setters (accessors) are not evil
  • They are "evil" (unnecessary) most of the time however
  • Encapsulation is not just adding accessors around private fields to control change, after all there is no benefit to added get/set methods that just modify a private field
  • You should write as much code as possible with the principle of "Tell, Don't Ask"
  • You need to use accessors for framework code, DTOs, serialisation and so forth. Don't try to fight this.
  • You want your core domain logic (business objects) to be as property free as possible however. You should tell objects to do stuff, not check their internal state at will.

If you have a load of accessors you essentially violate encapsulation. For example:

class Employee
{
   public decimal Salary { get; set; }

   // Methods with behaviour...
}

This is a crap domain object, because I can do this:

me.Salary = 100000000.00;

This may be a simple example, but as anyone who works in a professional environment can attest to, if there is some code that is public pe

answered 2012-02-29T21:48:18.257

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