Question

This is something that I’ve always wrestled with in my code. Suppose we have the following code:

public class MyClass {
    private string _myVariable;

    public string MyVariable {
        get { return _myVariable; }
        set { _myVariable = value; }
    }

    public void MyMethod() {
        string usingPrivateMember = _myVariable; // method A
        string usingPublicProperty = MyVariable; // method B
    }
}

Which way is more correct – method A or B? I am always torn about this. Method A seems like it would be minutely faster, due to the fact that it doesn’t have to go access a property before getting the real variable. However, method B is safer because if the getter for MyVariable gets business logic added to it, you are safe by always calling it, even if there is no current business logic.

What’s the general consensus?

Answer 1

Use the property.

I think the property should be wholly responsible for managing that field.

There are plenty of implementations where it won’t matter, but there are lots where it does matter — a lot. Plus, this can be a bit of a pain to track down, because it always looks right.

You’ll go wrong calling the property far fewer times than calling the field, and where there are exceptions to this rule, document the rationale.