I recently read that getters/setters are evil and I have to say it makes sense, yet when I started learning OOP one of the first things I learned was “Encapsulate your fields” so I learned to create class give it some fields, create getters, setters for them and create constructor where I initialize these fields. And every time some other class needs to manipulate this object (or for instance display it) I pass it the object and it manipulate it using getters/setters. I can see problems with this approach.
But how to do it right? For instance displaying/rendering object that is “data” class – let’s say Person, that has name and date of birth. Should the class have method for displaying the object where some Renderer would be passed as an argument? Wouldn’t that violate principle that class should have only one purpose (in this case store state) so it should not care about presentation of this object.
Can you suggest some good resources where best practices in OOP design are presented? I’m planning to start a project in my spare time and I want it to be my learning project in correct OOP design..
Allen Holub made a big splash with “Why getter and setter methods are evil” back in 2003.
It’s great that you’ve found and read the article. I admire anybody who’s learning and thinking critically about what they’re doing.
But take Mr. Holub with a grain of salt.
This is one view that got a lot of attention for its extreme position and the use of the word “evil”, but it hasn’t set the world on fire or been generally accepted as dogma.
Look at C#: they actually added syntactic sugar to the language to make get/set operations easier to write. Either this confirms someone’s view of Microsoft as an evil empire or contradicts Mr. Holub’s statement.
The fact is that people write objects so that clients can manipulate state. It doesn’t mean that every object written that way is wrong, evil, or unworkable.
The extreme view is not practical.