what is the purpose of static constructors

Some important point regarding static constructor from C# Language Specification and C# Programmer's Reference :

1) The static constructor for a class executes before any instance of the class is created.
2) The static constructor for a class executes before any of the static members for the class are referenced.
3) The static constructor for a class executes after the static field initializers (if any) for the class.
4) The static constructor for a class executes at most one time during a single program instantiation
5) A static constructor does not take access modifiers or have parameters.
6) A static constructor is called automatically to initialize the class before the first instance is created or any static members are referenced.
7) A static constructor cannot be called directly.
8) The user has no control on when the static constructor is executed in the program.
9) A typical use of static constructors is when the class is using a log file and the constructor is used to write entries to this file.

Reference Link :- Static Constructor in C# and their Usages.[^]

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http://msdn.microsoft.com/en-us/library/aa645612(v=vs.71).aspx[^]
http://www.dotnetperls.com/static-constructor[^]

What is: A static constructor is typically used to
initialize features that apply to a class rather than an instance. Thus, it is used to initialize aspects of a class before any objects of the class are created.

Points to be noted:

1.The static constructor is called automatically (when the class is first loaded) and before the instance constructor.

2.The static constructors cannot have access modifiers (thus, they use default access) and cannot be called by your program.

Usage:

1.A typical use of static constructors is when the class is using a log file and the constructor is used to write entries to this file.

2.Suppose we have a static class that uses database access then a static constructor is a handy place to initialize that database connection, because it means that the connection will get created right before it is first needed.

3.As you know each object occupies some space in memory. But by using static constructor we can reduce it. That means increase in performance.

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A static constructor is called automatically to initialize the class before the first instance is created or any static members are referenced

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