What is a primary constructor in modern C#?
PICTURE THIS: HOW TO EXPLAIN IT
Simple meaning
It declares constructor parameters on the type itself and can capture them as fields.
WHY — C# instead of guessing?
Why interviewers care about C#:
who only read docs from people who shipped.
and tied to .NET work.
Name the idea, why it exists, then one short example.
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:
- 1It declares constructor parameters
on the type itself and can capture them as fields.
- 2Why it exists
Great for simple DI-heavy classes.
- 3I still write a
full constructor when validation is complex.
- 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:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
It declares constructor parameters on the type itself and can capture them as fields. Great for simple DI-heavy classes.