Constant variable in C#

 What is Constant variable in C#?

In C#, a constant variable is a variable that cannot be changed after it has been initialized. A constant variable is similar to a read-only variable, but the value of a constant variable is determined at compile-time and cannot be changed at runtime.

You can declare a constant variable using the "const" keyword followed by the variable type and name:

class MyClass {

    public const int myConstVar = 10; // a constant variable

}

In this example, we declare a constant variable named "myConstVar" of type int in the MyClass class. We initialize the constant variable with the value 10. Once a value is assigned to a constant variable, it cannot be changed.

Constant variables are useful when you have a value that will never change throughout the execution of the program, such as pi (3.14159) or the speed of light (299,792,458 meters per second). By using a constant variable instead of a regular variable, you can ensure that the value will not be accidentally or intentionally modified at runtime. Constant variables are also used to improve code readability and maintainability by giving meaningful names to commonly used values.