In C#, is there a clean way of checking for multiple levels of null references

Question

For example, if I want to call the following: person.Head.Nose.Sniff() then, if I want to be safe, I have to do the following:

if(person != null)
    if(person.Head != null)
        if(person.Head.Nose != null)
            person.Head.Nose.Sniff();

Is there any easier way of formulating this expression?

Answer 1

Is there any easier way of formulating this expression?

With C# 6, you can use the null-conditional operator ?.

Code example

This is your original code packed into a method and assuming Sniff() always returns true:

    public bool PerformNullCheckVersion1(Person person)
    {
        if (person != null)
            if (person.Head != null)
                if (person.Head.Nose != null)
                    return person.Head.Nose.Sniff();
        return false;
    }

This is your code rewritten with the C# 6 null-conditional operator:

    public bool PerformNullCheckVersion2(Person person)
    {
        return person?.Head?.Nose?.Sniff() ?? false;
    }

The ?? is the null-coalescing operator and is not related to your question.

For the full example, see: https://github.com/lernkurve/Stackoverflow-question-3701563