> For the complete documentation index, see [llms.txt](https://gyansetu-java.gitbook.io/core-java/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gyansetu-java.gitbook.io/core-java/interfaces/extending-interfaces.md).

# Extending Interfaces

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By extending interfaces, you can combine methods of multiple interfaces. In the previous example, the interface FamilyPGHouse combines the methods of the interfaces ChildFriendly, PayingGuestHouse, and GuestHouse. When a class implements an interface, it should implement all the methods defined in the interface and its base interfaces, unless it’s declared as abstract. If, for example, a class implements the interface PayingGuestHouse, that class must implement method paidBreakfast() defined in the interface PayingGuestHouse, and method welcome() defined in the interface GuestHouse.

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