To learn more, see our tips on writing great answers. An interface extends another interface using the keyword extends. How to show the desired region when using ListDensityPlot. From the end result standpoint you could just use multiple interfaces in place of handling a hierarchy (just as you could avoid using inherited behavior in a class hierarchy). If a class is implementing the interface B, then the class must implement methods from both the interface B and A as shown in below example. Note that even though class XYZ is implementing the interface B, the interface A is automatically available to the class as interface B is extending the interface A. You can now choose to sort by Trending, which boosts votes that have happened recently, helping to surface more up-to-date answers. In java, an interface can extend another interface. I hope this helps! a membership test via the member method. Learn how an interface extends interface in java with example. In the first case the coder of class C does not need to know the detail that B inherits A, he just needs to read the documentation for B. If A is Car and B is SportCar, you might want to use just Car interface to handle some flows, but sometimes need to be more specific and use explicitly SportCar. I'm not saying the practice should be blindly adopted, but you're saying it should be wholly avoided so it's more on you to respond to the Iterable comment. position in the type hierarchy. An interface can inherit or say, can extends another interface or other multiple interfaces in java programs. Connect and share knowledge within a single location that is structured and easy to search. The same rule holds for How can I use parentheses when there are math parentheses inside? Since the formal parameter T satisfies the lt where clause of SortedList, test (equals), and SortedList_Member objects also order their That thread covers a particular instance which you're generalizing ambitiously. When interface inherits another interface, we use extends keyword as given in example below. Is a neuron's information processing more complex than a perceptron? a formal parameter. But, in your second example, you don't declare B to extend A, so the code above wouldn't work. How would you make it also implement Car interface? The reasons for this rule As far as I know, there is no way to add a type that consists of multiple interfaces. I'm not going to research examples for you but I'd wager the Collections API is full of them. Why does the capacitance value of an MLCC (capacitor) increase after heating? What's inside the SPIKE Essential small angular motor? of SortedList_Member states that it extends SortedList[T]. Scraping off a single layer and evaluating extending Iterable alone is more representative. Because, for example. Here are three examples: As in ordinary Java, all subtype relations for instantiations the AutoCloseable interface in Java 7. How APIs can take the pain out of legacy system headaches (Ep. In your first example, your new interface B is defined to extend from A, so going forward, any class that implements B automatically implements A. even if BigNum is a subtype of Num. That's exactly the meaning of inheritance in OOP. The rule for the legality of an extension is particularly simple: Making statements based on opinion; back them up with references or personal experience. The interface that extends another interface has its own members and all the members defined in its parent interface too. being defined. This way you can't promise that myCar would have a method of Car (like Drive()), which looses the advantage that was gained from inheritance.