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What is inheritance ???

16th Mar 2017, 11:31 AM
Marshall Moyo
Marshall Moyo - avatar
2 Respuestas
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Inheritance refers to the "handing down" of traits possessed by a parent element. If you code a function within a function, that "child" function will "Inherit" some of the traits that the "Parent" function has set for it. (Unless explicitly told not to) Hope this helps!
16th Mar 2017, 3:30 PM
FastTrack Programming
FastTrack Programming - avatar
+ 1
Inheritance allows you to easily share code between multiple classes. This includes methods and fields. For example, let's say that you are making a game, which will need some animals. You can create an animal superclass: public class Animal { // traits that all animals (of any type) must have: private int health = 100; // behavior (methods) that all animals (of any type) must have: public int getHealth() { return health; } public void damge(int damage) { health -= damage; // subtract 'damage' from this animals health } } So now, whenever we want to make a new type of animal, we extend the animal class: public class Dog extends Animal { // traits that all dogs must have private DogBreed breed = //... // behavior that all dogs must have: public void bark() { System.out.println("Bark!"); } } Now, if you create a new Dog object: Dog dog = new Dog(); You can call the dog's method (of course): dog.bark(); But you can also use the Dog object to call a method defined in the Animal class: dog.damage(1); // we don't have to re-redefine this in the dog class, because the Animal class (Dog's superclass) already defines this method. It is also possible to override a method (so if we wanted to make dogs invincible - which, of course, we do!). This can be done by copying the superclass's method header (which is the stuff at the top, such as the return type, method name, parameters, etc): @Override // optional line, indicates that this method overrides a superclass method public void damage(int damage) { // do nothing - we don't want this dog to take damage! } Inheritance is very powerful, and definitely a topic worth looking into.
16th Mar 2017, 6:42 PM
Kevin