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.
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 variable
Note: Now the above-declared variables are constant, it means that their values can't be changed during execution of the program.
Test Your Knowledge
Attempt the multiple choice quiz to check if the lesson is adequately clear to you.