Why do you use interfaces in java?

Answer 1

An interface is used in java to outline specific behaviors of a group of classes, i.e. Comparable (able to be compared). These common behaviors translate into methods that are all public and unimplemented (since an interface lists what can be done not how). An interface is usually used when it doesn't make sense for something to be a class but it does have general behaviors that other classes should implement, i.e. there is not much sense to implement a Comparable class, since many different objects have vastly different ways to compare each other; thus, the behavior is outlined, and future classes can implement said behaviors (the methods).

Answer 2

An interface is a contract that guarantees that classes which implement the interface will have certain methods available. This allows the calling class to use the given object's methods without having to know details about its type.

Answer 3

we use interface in java to implement the concept of late binding.

LATE BINDING:the concept of binding of the functionalites to the function definitions at run-time is know as late binding

Answer 4

It is advisable to design relatively large applications using interfaces because it makes the whole system easier to modify, extend and integrate new features. To start with you may only have one implementation of a given interface, but if you find you need slightly different behaviour in special circumstances, you only need write a class that conforms to one of the existing interfaces and it will drop in place without major modifications.

Interfaces also allow you to adapt a class from a different hierarchy to work in an existing application. The class only needs to declare it implements the interface, provide the necessary methods and it can be integrated directly as if it were created for the job.

The above describes a good reason to use Interfaces, but does not explain why Java has interfaces in the first place (which is what the question really is asking).

Java uses Interfaces to simulate the concept of Multiple Inheritance. As Java itself is a strictly Single Inheritance design, specifically to avoid the problems that Multiple Inheritance can cause, the addition of Interfaces was made to gain as many of the advantages of M.I. without the corresponding faults.

Answer 5

Interfaces are a way to make your code more flexible.Interfaces are used to achieve "Polymorphic" behavior. Interface is just like Java class but it contain only abstract method and final attribute.

For more information, you can follow-

marcus-biel.com/java-interfaces/

YouTube.com/watch?v=8ybdWHKSlP8

Answer 6

With interfaces, you can be sure that a class implements a particular behavior. For example, if a class has the "comparable" interface, you can be sure that objects based on the class can be sorted, by calling appropriate methods to determine whether one object should be placed before or after another object.