Constant Variable in C++ Programming
C++ Basic Concepts
In this lesson, we will look at what is constant variable and how to declare one with the help of some example. We will also play a quiz at the end.
What is Constant Variable
A Constant variable in C++ is a variable whose value does not change during the execution of the program. Once a value is assigned, in a constant variable, it remains fixed throughout the program. A Constant variable is declared by keyword const.
Syntax of Declaring Constant Variable in C++
const datatype variable_name;Here const is used for declaring Constant, datatype is the name of data type such as int, float, double or char and variable_name is the name of variable (you can use any name of your choice for example: a, b, c, alpha, etc.) and ; is used for line terminator (end of line).
Now let's see the example for more understanding.
Example
Declare constant variables of each datatype.
const int a = 23; // a becomes integer constant variable
const float b = 56.36; // b becomes float constant variable
const double c = 75.3215; // c becomes double constant variable
const char d = 'k'; // d becomes character constant variableNote: Now the above-declared variables are constant, it means that their values can't be changed during execution of the program.
