Zero. By default they do not implement any interfaces.
Java does not support multiple inheritance. It is done with the help of interfaces in java. a class can implement n number of interfaces, thus showing multiple inheritance. but a class cannot extend multiple classes in java.
Java does not support multiple inheritance; a subclass cannot have more than one parent. Java compensates for this with interfaces. A class can implement multiple interfaces, but can only extend one class.
Any class can extend one class and/or implement multiple interfaces. For example: public class TestClass extends SuperTestClass implements InterfaceA, InterfaceB { // implementations of interface methods in here }
In java we can implement more than one interfaces for a single class but we can't extend a class to more than one super class so ,java indirectly supports multiple inheritance.
A non-instantiable class is the class whose object can be created but cannot be initialized. for example the interfaces and the abstract classes in java.
Java does not have multiple inheritance, so no. Java can use multiple interfaces, though, with the "implements" keyword.
A non-instantiable class is the class whose object can be created but cannot be initialized. for example the interfaces and the abstract classes in java.
Actually, java does not support multiple inheritance. You can achieve partial multiple inheritance using interfaces but java is not like C or C++ where you can do direct multiple inheritance. However, you can achieve partial multiple inheritance with the help of interfaces. Ex: public class FerrariF12011 extends Ferrari implements Car, Automobile {
Java does not allow the multiple inheritance of concrete classes, though it does allow a "hybrid" inheritance of one concrete class and multiple interfaces.
Interfaces are used in Java to accomplish most of the goals of Multiple Inheritance. For several reasons, Java only supports Single Inheritance for classes - i.e. a class can have only a single parent. The use of Interfaces is how Java attempts to implement most of the positives of the concept of Multiple Inheritance while avoiding its pitfalls.
The short answer: because C is not object-oriented. The reason for C++ not having interfaces is, that C++ supports multiple inheritance. Because C++ classes can be derived from more than one base class, so there is no need to have interfaces. In Java, each class has exactly one base class (except the class Object). With the help of interfaces it is possible implement a restricted (and more stable) form of multiple inheritance. Interfaces follow implicitly the following rules: * interfaces are abstract * each method is public abstract * each attribute is public static final
Multiple Inheritance cannot be achieved only by using Classes in Java. You would have to use Interfaces as well to achieve multiple Inheritance. Java as such does not support direct multiple inheritance. We can have theoretical multiple inheritance by using interfaces using which you can outline the kind of functionality your child classes can have. For example you can have a declaration like this public class A implements X, Y, Z { } Here this class A would have to implement the methods that are declared in the interfaces X, Y & Z. So the outline of the functionality that A would have can be found by checking the interfaces but the exact implementation would depend on the programmer who codes class 'A'