Why can I declare a member variable of an interface not static? It is implicitly static (and final ) (which means it is static even if you omit the static keyword), as stated in the JLS: Every field declaration in the body of an interface is implicitly public , static , and final . read more
every variable inside interface is by default public , static, final.. but you can create a non-static variable in java-8 ,, all you have to do . is: create variable but not initialze . you have to implement this interface to a class and make a objeeect , to access those variables. read more
Interfaces can only have static member variables. Method signatures normally are non-static because they need to be implemented (as of Java 8 there are static default implementations but those are more of a special case). read more
No.We can not create non static variables in an interface. If we try to create non static variables compile time error comes. By default members will be treated as public static final variables so it expects some value to be initialized. read more