What is a nullable value type?
PICTURE THIS: DATABASE INDEX
Without indexScan every row
With indexJump to keys
CostWrites slower
WHY — C# instead of guessing?
Why interviewers care about C#:
C# questions separate people
who only read docs from people who shipped.
Keep it short, concrete,
and tied to .NET work.
Stay structured
Name the idea, why it exists, then one short example.
Close cleanly
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1is Nullable of int,
so it can hold null as well as a number.
- 2HasValue and Value, or
the ??
- 3operator, are how I
unwrap it.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Say this line
“operator, are how I unwrap it.”
Break into beats
operatorarehowIunwrapit
Speaking order
2987408337471632900
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
is Nullable of int, so it can hold null as well as a number. HasValue and Value, or the ??