What does const correctness mean?
PICTURE THIS: 1, 2, 2, 8
Simple meaning
I mark methods and params const when they should not modify state.
WHY — Basics instead of guessing?
Why interviewers care about Basics:
who only read docs from people who shipped.
and tied to C++ 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:
- 1I mark methods and
params const when they should not modify state.
- 2Why it exists
The compiler enforces that promise.
- 3It documents intent and
catches bugs early.
- 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
I mark methods and params const when they should not modify state. The compiler enforces that promise.