Static Class C#

A static class cannot be instantiated. In other words, you cannot use the new keyword to create a variable of the class type.

·         Contains only static members.

·         Is sealed.

·         A non-static class can contain static methods, fields, properties, or events.

·         Always accessed by the class name

·         It is more typical to declare a non-static class with some static members, than to declare an entire class as static.

·         Static methods and properties cannot access non-static fields and events

·         Static fields store a value that must be shared among all instances.

·         Static methods can be overloaded but not overridden

·         C# does not support static local variables (variables that are declared in method scope).

·         Static members are initialized before the static member is accessed for the first time and before the static constructor, if there is one, is called.

·          Static class can make your implementation simpler and faster because you do not have to create an object in order to call its methods.

·         No instantiation, no disposal, just fire'n'forget.

·         An abstract class is usually intended to model something in a type hierarchy. For example, a truck is a kind of vehicle. A static class by contrast is not intended to model anything at all. It's just a convenient way of storing a bunch of code.

·         Static" on a class, what we actually do is generating an abstract sealed class with no public constructors. Since it is abstract, you cannot create one directly. Since it is sealed, you cannot create a more derived class and instantiate that.

·         Cannot contain Instance Constructors.( Instance constructors are used to create and initialize any instance member variables when you use the new expression to create an object of a class.)

Instance constructors Eg

class Add

{

    public int x, y;

    // constructor 

    public Add()

    {

        x = 0;

        y = 0;

    }

}

EG Console.WriteLine(Math.Abs(dub));

Here Math is a static class