Static Constructor

• Static Constructor is used to initialize static Data fields
• Static Data Fields will have maintained only one instance for any no of objects created to the class
• To make any member of a class static, use static keyword
• Static members are not accessible with object rather; we need to access with class name only
• There can be only one static constructor in the class
• The static constructor should be without parameters
• It can only access the static members of the class
• There should be no access modifiers in static constructor definition
• If a class is static, then we can’t create object for static class
• Static constructor will be involved only once i.e., 1^st object created for the class from second object onwards static constructor will not be called

Example:-

Class Diagram :-

using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace CAConstructors {     class ClsSample     {         int v;         static int s;         public ClsSample()         {             v = 9;         }         static ClsSample()         {             s = 9;         }         public void Display()         {             Console.WriteLine("value of i is    :-  " + v);             v++;             Console.WriteLine("value of j is    :-  " + s);             s++;         }     }     class ClsSConstructor     {         static void Main()         {             ClsSample Obj1 = new ClsSample();             Obj1.Display();             ClsSample Obj2 = new ClsSample();             Obj2.Display();             ClsSample Obj3 = new ClsSample();             Obj3.Display();             ClsSample Obj4 = new ClsSample();             Obj4.Display();             Console.Read();         }     } }

Output :-

• It’s not possible to Initialize non-static Data Fields, with in the static constructors, it raises compilation error

         static ClsSample( )

        {

                v=100//Not allowed

                 s=100;

        }

• We can initialize static Data fields with a non-static constructor but they lose their static nature

          public ClsSample( )

         {

               v=100;

               s=100; //Allowed But loses its static nature

          }

• We can initialize static Data fields in both static and non static constructors but static Data Fields will lose their static nature

        public ClsSample( )

       {

               v=100;

                s=100; //Allowed But lose its static nature

        }

        static ClsSample( )

       {

             s=100; //Allowed

        }