An interface can't contain instance fields, instance constructors, or finalizers. Interface members are public by default, and you can explicitly specify accessibility modifiers, such as public , protected , internal , private , protected internal , or private protected .

Should interface have fields?

An Interface specifies a contract, which a concrete class that implements the Interface must adhere to. ... Fields are an implementation detail, as fields do not describe how a class should "act as." For instance, Interfaces are commonly used as a declared type and a concrete implementation is used as an actual type.

What is a field in an interface?

In an interface all the fields (variables) are by default public, static and final. ... An interface can have default methods and static methods. Any other methods are implicitly public and abstract. All the fields declared in an interface are implicitly public, static and final constants.