Difference between import and extends in java?

Answer 1

Import brings all the stuff of a file/API where you have imported it and increases redundancy while inheritance reduces redundancy, increase efficiency of code & makes it manageable. And most important point to remember is that, inheritance is a design followed over the whole project to archive polymorphism.

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Vaibhav Singh

Answer 2

Extending a class means creating a subclass, also known as a derived class, or a child class, from a class.

Importing a class simply means making the class available, so you can create objects based on the class.

Extending a class means creating a subclass, also known as a derived class, or a child class, from a class.

Importing a class simply means making the class available, so you can create objects based on the class.

Extending a class means creating a subclass, also known as a derived class, or a child class, from a class.

Importing a class simply means making the class available, so you can create objects based on the class.

Extending a class means creating a subclass, also known as a derived class, or a child class, from a class.

Importing a class simply means making the class available, so you can create objects based on the class.

Answer 3

All a "import" statement does is make it so that you only have to type the class name, and not the package name each time you use it. Extends means that your class is actually a instance of that class. Your class would behave as if it were one of the class you are extending from, except it may implement functionality differently, and add extra functionality.

Answer 4

A derived class automatically inherits all the public and protected members of its base class, which it can override if necessary. By percolating all common functionality up to the base class, the derived class can inherit that common functionality, augment it and make it more refined, without having to rewrite the common code itself. As a result, consumers of the base class can use the common interface, irrespective of the classes that are derived from it. They will all do what is expected of them by their inherited interfaces.

Delegation is where one class method calls a method in another class that is better able to deal with the call. To use an analogy, a telephone exchange is not concerned with the individual ringtone produced by each of the telephones that are connected to it. It only needs to know how to make a phone ring, and delegate the work of actually ringing to the telephone itself. In other words, it only needs to know what it does, not how it actually does it.

Similarly with classes that contain other classes. The containing class doesn't require any intimate knowledge of all the classes it contains. By delegating calls to the contained classes, the containing class essentially gets all the credit, but does none of the actual work.

Delegation can also be applied to inheritance. A derived object may override a base class function in order to refine it, but is still free to delegate the call to the base class rather than duplicate the code it contains. Again, the derived class is not concerned with the inner workings of its base class. It is only concerned with what it does, never how it does it (this is otherwise known as encapsulation and data-hiding).

Answer 5

Extending a class means creating a subclass, also known as a derived class, or a child class, from a class.

Importing a class simply means making the class available, so you can create objects based on the class.