What is const in cpp?

Answer 1

A constant is an expression with a fixed value. It cannot be changed while the program is running.
Use the const keyword to define a constant variable.
https://www.sololearn.com/learn/CPlusPlus/1895/

Answer 2

For example
const float pi = 3.14;

As you don't want to change value any time during the execution this won't let you do it by mistake.

Answer 3

If we declare value as a const in a program we can't change that value, That value is fixed value in that program