What is the purpose of inheritance in Java?

Inheritance is a fundamental concept in object-oriented programming and is used to create new classes that reuse, extend, and modify the behavior of existing classes. It allows a new class to inherit the characteristics of an existing class, which can save time and simplify the code. In Java, inheritance is implemented using the extends keyword.

The main purpose of inheritance is to provide code reusability. In Java, a subclass can inherit fields and methods from a superclass, which means that the subclass does not have to re-implement them. This can help reduce the amount of code that needs to be written, tested, and maintained.

Another purpose of inheritance is to allow polymorphism, which means that an object can take many forms. For example, if you have a class hierarchy with a superclass Animal and subclasses Dog, Cat, and Bird, you can create an array of Animals and put instances of any of the subclasses in it. Then, you can call the same methods on each object, even though they are different classes, which can simplify your code and make it more flexible.

Java supports both single and multiple inheritance through interfaces. An interface is a contract that specifies a set of methods that a class must implement. A class can implement multiple interfaces, which allows it to inherit behavior from multiple sources.