Interface can inherit

Nov, 8. Apr, Apr, 1. Feb, 2. You can't inherited because there is no inheritance concept this is Implementation. Jan, Dec, Nov, Oct, Yes 0. Developer Programmer Sr. In addition, you must use an interface if you want to simulate inheritance for structs, because they can't actually inherit from another struct or class.

You define an interface by using the interface keyword as the following example shows. The name of an interface must be a valid C identifier name. By convention, interface names begin with a capital I. A class or struct can implement multiple interfaces, but a class can only inherit from a single class. Interfaces can contain instance methods, properties, events, indexers, or any combination of those four member types.

Interfaces may contain static constructors, fields, constants, or operators. 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. A private member must have a default implementation. To implement an interface member, the corresponding member of the implementing class must be public, non-static, and have the same name and signature as the interface member.

When a class or struct implements an interface, the class or struct must provide an implementation for all of the members that the interface declares but doesn't provide a default implementation for.

However, if a base class implements an interface, any class that's derived from the base class inherits that implementation.

The implementing class, Car , must provide an implementation of the Equals method. Properties and indexers of a class can define extra accessors for a property or indexer that's defined in an interface. For example, an interface might declare a property that has a get accessor. The class that implements the interface can declare the same property with both a get and set accessor.

However, if the property or indexer uses explicit implementation, the accessors must match. For more information about explicit implementation, see Explicit Interface Implementation and Interface Properties. Interfaces can inherit from one or more interfaces. In Java, are interface members inherited by classes which implement them? Do we typically say in Java that a class inherits from an interface? Does this subtle distinction matter in day-to-day work?

Improve this answer. Community Bot 1. Eric Lippert Eric Lippert 45k 21 21 gold badges 86 86 silver badges bronze badges. I can't argue with a canonical reference. When specifications differ, as they necessarily do, simple terms become semantically overloaded and ambiguous out of context. The question is tagged with java so this is the right answer, unless the OP meant some other java :- — Jodrell.

Although the question is tagged with Java, I find it problematic to cite a language specification for a generic term. Many languages have interfaces and their language specs may use a different term, so using a Java-specific term may be confusing when talking to developers who use X-Lang. ThomasOwens: I agree that this scenario is common and I completely disagree with your conclusion.

The solution to the communication problem you describe is educate everyone involved as to the precise meanings of the words in the relevant context. Specifications exist to provide this clarity; use them!

Why would the Java language specification get the final say here? Language specification often claim things that the "common developer" disagrees with about terminology.

BenjaminGruenbaum: Don't I know it. Those developers are wrong, and they often take it upon themselves to "educate" others as to their wrong beliefs. You would not believe the number of programming language books I've had to fix because the authors had some completely crazy beliefs about VB, C , JavaScript, etc, that were in no way correct. Jon Skeet was not among them; C In Depth was correct from the start!

Never have I made so few comments on a book and still gotten paid. Show 23 more comments. Kilian Foth Kilian Foth k 43 43 gold badges silver badges bronze badges. GoF book seem to consider interface inheritance appropriate term to describe subtyping Section 1. He explained that the real problem wasn't classes per se, but rather implementation inheritance the extends relationship.

Interface inheritance the implements relationship is preferable. You should avoid implementation inheritance whenever possible. Add a comment. With subclasses , you inherit state of the superclass all instance variables, whether you see them or not inherit actual implementations all non-abstract methods With interfaces , you fullfill a contract by implementing the declared methods.

Now with Java 8 the interfaces become a mixture: you still don't inherit state as interfaces still don't have instance variables you now can inherit default implementations from the interface Would implementing an interface whose methods all have default implementations still count as 'implement', or rather as extension? Peter Walser Peter Walser 3 3 silver badges 7 7 bronze badges. The Overflow Blog. Does ES6 make JavaScript frameworks obsolete?

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