Modern C++ for Absolute Beginners: A Friendly Introduction to the C++ Programming Language and C++11 to C++23 Standards

© The Author(s), under exclusive license to APress Media, LLC, part of Springer Nature 2023

S. DmitrovićModern C++ for Absolute Beginnershttps://doi.org/10.1007/978-1-4842-9274-7_17

17. Constants

Slobodan Dmitrović¹  

(1)

Belgrade, Serbia

 

When we want to have a read-only object or promise not to change the value of some object in the current scope, we make it a constant. C++ uses the const type qualifier to mark the object as a read-only. We say that our object is now immutable. To define an integer constant with a value of five, for example, we would write

int main()

{

    const int n = 5;

}

We can now use that constant in places such as an array size:

int main()

{

    const int n = 5;

    int arr[n] = { 10, 20, 30, 40, 50 };

}

Constants are not modifiable. ...