Gain insights into the C++ keyword 'const,' its usage in various contexts, and implications when returning pointers and references. Learn about preventing accidental data changes.

How to use const in C++ by Sándor Dargo_468 x 60 copy.png

In this course, you will learn about the C++ keyword const and its behaviour under different usage conditions, including local, global and static contexts. This course will help you to understand const and its implications when you attempt to return pointers and references in C++. By the end of the course, you will have a solid grip on const and its usage in preventing any accidental change of data.

Secure Coding Practices in C++: A Deep Dive into const

Why isn’t it a good idea to take primitive data type parameters by const reference?


Why isn’t it a good idea to take primitive data type parameters by const reference?

Pass them by `const&` if you don’t have to modify them, otherwise by reference.

What is the general rule for passing class type parameters?


What is the general rule for passing class type parameters?

When you have made a local copy of it in order to locally modify its value.


If the size of the class type is small and according to your measurements, passing const& doesn’t increase performance.

When you don’t want to change the value.

In what situation should you consider passing a class type parameter by value? Select all that apply.


In what situation should you consider passing a class type parameter by value? Select all that apply.

They can match in terms of constness of parameters and should be ambiguous.

Yes, they must have to match completely.


There can be differences in terms of constness of the parameters as long as they are not ambiguous.

To what degree do the parameter list of a function declaration (header file) and definition (implementation file) have to match?

To what degree do the parameter list of a function declaration (header file) and definition (implementation file) have to match?

Here's a short quiz to test your understanding.

Introduction

Arguments using const

Local Variables

Local Members

Functions

Return Types

const Parameters

const and Smart Pointers

Rvalue References

Summary

Quiz