What is a Static Constructor?

A static constructor is a special constructor used to initialize static members of a class. It is called automatically once only, when the class is accessed for the first time.

Key Features

• Has no parameters.

• Cannot be called explicitly.

• Automatically called once per type, not per object.

• Used to initialize static fields or perform any one-time setup.

Syntax

class ClassName
{
    static ClassName()
    {
        // Initialization code for static fields
    }
}

Simple Example

using System;
class AppConfig
{
    public static string version;
    // Static constructor
    static AppConfig()
    {
        version = "1.0.0";
        Console.WriteLine("Static constructor called");
    }
    public static void ShowVersion()
    {
        Console.WriteLine("App Version: " + version);
    }
}
class Program
{
    static void Main()
    {
        // First access triggers the static constructor
        AppConfig.ShowVersion();
    }
}

Output:

Static constructor called  
App Version: 1.0.0