What is Use of Static Constructor and When to Use it

A static constructor is a special type of constructor in C# that is used to initialize static data members or to perform any other type of static initialization. It is called automatically by the runtime before the first instance of the class is created or before any static members are accessed.

Here are some use cases for static constructors:

Initializing static data members

If you have static data members in your class that need to be initialized before they are used, you can use a static constructor to perform the initialization. This ensures that the static data members are initialized before any instance of the class is created or before any static members are accessed.

Registering event handlers 

If your class needs to register event handlers for static events, you can use a static constructor to perform the registration. This ensures that the event handlers are registered before any instance of the class is created or before any static members are accessed.

Setting up static configuration

If your class needs to read static configuration settings from a file or database, you can use a static constructor to perform the setup. This ensures that the configuration is read before any instance of the class is created or before any static members are accessed.

Performing other types of static initialization

If your class needs to perform any other type of static initialization, such as setting up a static cache or initializing a static database connection, you can use a static constructor to perform the initialization.

It's important to note that a static constructor is only called once, regardless of how many instances of the class are created or how many times static members are accessed. It is also called automatically by the runtime, so you don't need to explicitly call it in your code.