Moderate Rule of Five Question 19 of 208

What is the rule of three or five?

C++ interview set · Speak this in 60–90 seconds · Faridabad & Delhi NCR

PICTURE THIS: HOW TO EXPLAIN IT

IdeaRule of Five

HowWhat happens inside

Why they askShows real use

Simple meaning

If I write a destructor, copy constructor, or copy assignment, I likely need all three.

WHY — Rule of Five instead of guessing?

Why interviewers care about Rule of Five:

Rule of Five questions

separate people who only read docs from people who shipped.

Keep it short, concrete,

and tied to C++ 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:

1
If I write a
destructor, copy constructor, or copy assignment, I likely need all three.
2
With C++11 I also
consider move constructor and move assignment.
3
Prefer rule of zero:
members that already manage resources, like vector and unique_ptr.
4
Give an example
One tiny concrete case you can say aloud.
5
Common mistake
What juniors usually get wrong.
6
Close
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

“With C++11 I also consider move constructor and move assignment.”

Break into beats

WithC11Ialsoconsider

Speaking order

2987408337471632900

Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.

Key takeaway

If I write a destructor, copy constructor, or copy assignment, I likely need all three. With C++11 I also consider move constructor and move assignment.