Is passing null in to a method acceptable

Question

Null is an odd data type for me, it seems as though it is wrong to ever use, maybe its the null pointer errors i got so often as a beginner that now have me associating any

Answer 1

It is absolutely fine to pass null to methods. However, if you have a csae where you might not need to pass a variable, consider overloading.

The reason why you might pass a null is because you might have a method with quite a few parameters and you do not wan to implement all possible overloads.

I personally would not use optional parameters - there are many discussions on this very subject because of the issue with the method as Contract which is outside the scope of this question.

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UPDATE

Correct way to do it is not to duplicate code but let overloads call each other:

public void Foo(A a)
{
    Foo(a, null);
}
public void Foo(A a, B b)
{
        // .......
}

This will tell client of this code:

• You can call method with A only
• You can call method with A and B

If I have only the second method, the client would not know if it is OK to pass null.