Static

Static keyword has different role in different places for C#. When we declare static that means only single copy will be generate.

Static container can only contains static members

It is used in below places-

• Class
• Method
• Field
• Properties
• Constructor

Static Class

• Only contain all static members like static methods, static fields, static properties and static constructor.
• Any instance or non-static member can not be there in the Static Class.
• If we need to create all the members as static then we can create static class.
• Can not create instance of such class.
• Sealed.
• Cannot contain Instance Constructors

Static Methods

• Only contain all static fields
• Non-static fields are not allowed in static methods
• Method can be access using class only, no instance is needed or can access.
• Single copy of static method will be shared among all the instances.

Static Fields

• Single copy of fields/variables get created and shared among all the instances.
• If static variable value has been change using one instance then all other instance will get that changed value.

Static Property

• Can be access using class only.
• Using instance it can not be access.

Static Constructor

• Access modifier are not allowed.
• Static Constructor as it(class constructor) execute prior to any other constructor (instance constructor).
• Can instantiate value of static fields only.
• Non-Static fields is not allowed within the scope.

More About Static:

• Static methods are not allowed in the interface.
• Access modifiers are not allowed in the interface and static constructor.
• Static class can't be inherit from interface/class/static class.
• Static class can only be inherit from object. ??
• Inheritance from static class in not possible as static classes are sealed.
• Inherited Static method can not be marked as override, virtual or abstract.
• Inherited Static methods can be marked as new.