Difference between constant variable and static variable in C#

 What is difference between constant variable and static variable in C#?

The main difference between a constant variable and a static variable in C# is that a constant variable is initialized at compile-time and cannot be changed at runtime, while a static variable is initialized only once at runtime and can be changed throughout the lifetime of the program.

Here are some key differences between constant and static variables in C#:

- Initialization: A constant variable must be initialized at the time of declaration, while a static variable can be initialized either at the time of declaration or in a static constructor.

- Value: A constant variable has a fixed value that cannot be changed at runtime, while a static variable can be changed throughout the lifetime of the program.

- Memory allocation: A constant variable is stored in the application metadata and is not allocated any memory at runtime, while a static variable is allocated memory at runtime and is stored in the heap.

- Scope: A constant variable is accessible only within the same class or struct in which it is defined, while a static variable is accessible throughout the program.

- Usage: A constant variable is typically used for values that do not change, such as mathematical constants or configuration settings, while a static variable is used for values that need to be shared among all instances of a class, such as counters or cache data.

In summary, constant variables are used for values that never change, while static variables are used for values that can change but need to be shared among all instances of a class.