Static constructor in C# - in 3 steps

To initialize the class before the first instance is created, a static constructor is called automatically. A static constructor is not called directly and does not take parameters. A static constructor is executed in the program automatically and a user has no control on it. Static constructor initializes static data members when the class is referenced first time. The difference between an instance constructor and a static constructor is, an instance constructor is used to initialize data whereas a static constructor is used to initialize only static members.

In c#, we declare a static constructor using a 'static ' keyword. In the code given below, we have declared static variable 'i'. In the static constructor, we have initialized static variable 'i' to zero.

public class ItemClass
{	private string ItemCode;
	private string ItemName;
	private string Itemdescription;
	private string ItemCategory;
	private double ItemPrice;
	private string ItemUnit;
	static int i;

	public ItemClass()
	{	i=i+1;
		ItemCode = "Ioo1";
		ItemName = "Reading Guage";
		Itemdescription = "Trading";
		ItemCategory = "Instruments";
		ItemPrice = 10;
		ItemUnit = "Kgs";
		MessageBox.Show("The number of instances are:"+i); 
	}
	static ItemClass()
	{
		i = 0;
	}
}