Can one interface extend multiple interface?
Answer is: Yes. An interface may be declared to be a direct extension of one or more other interfaces, meaning that it implicitly specifies all the member types, abstract methods, and constants of the interfaces it extends, except for any member types and constants that it may hide.
Can a class implement more than one interfaces?
Your class can implement more than one interface (the Java platform supports multiple inheritance for interfaces), so the implements keyword is followed by a comma-separated list of the interfaces implemented by the class. By Convention: The implements clause follows the extends clause, if it exists.
Can a class have multiple extends?
You can only Extend a single class. And implement Interfaces from many sources. Extending multiple classes is not available.
Why you can implement multiple interfaces but can extend only one class?
Since interfaces cannot have implementations, this same problem does not arise. If two interfaces contain methods that have identical signatures, then there is effectively only one method and there still is no conflict.
Can an interface inherit a class?
Interfaces can inherit from one or more interfaces. … A class that implements a derived interface must implement all members in the derived interface, including all members of the derived interface’s base interfaces. That class may be implicitly converted to the derived interface or any of its base interfaces.
Can an interface extend abstract class?
Abstract classes are typically used as base classes for extension by subclasses. … Remember, a Java class can only have 1 superclass, but it can implement multiple interfaces. Thus, if a class already has a different superclass, it can implement an interface, but it cannot extend another abstract class.
Can two interfaces have same method?
Interfaces can now contain methods with implementations. … So, if the class already has the same method as an Interface, then the default method from the implemented Interface does not take effect. However, if two interfaces implement the same default method, then there is a conflict.
Can a class implement another class?
A class can implement more than one interface at a time. A class can extend only one class, but implement many interfaces. An interface can extend another interface, in a similar way as a class can extend another class.
Can a class extend multiple abstract classes in Java?
A: Java has a rule that a class can extend only one abstract class, but can implement multiple interfaces (fully abstract classes).
Can a class inherit multiple classes in Java?
When one class extends more than one classes then this is called multiple inheritance. … Java doesn’t allow multiple inheritance.
Can Java inherit multiple classes?
The Java programming language supports multiple inheritance of type, which is the ability of a class to implement more than one interface. An object can have multiple types: the type of its own class and the types of all the interfaces that the class implements.
Can an interface be final?
An interface is a pure abstract class. Hence, all methods in an interface are abtract , and must be implemented in the child classes. So, by extension, none of them can be declared as final .
Can we extend interface in Java?
An interface can extend other interfaces, just as a class subclass or extend another class. However, whereas a class can extend only one other class, an interface can extend any number of interfaces. The interface declaration includes a comma-separated list of all the interfaces that it extends.