All language subtitles for 001 Inheritance_en

A class can inherit properties from another class.

Every class in Java has a common ancestor, the object class.

In this lesson, you're going to learn about inheritance.

The object class is the ancestor of every class.

Every class inherits methods from the object class.

Here's the source code for the object class, it's a bit hard to read on the website, so I cleaned

it up for you.

So please open the folder for this lesson by navigating that this path and the resources.

You'll notice inside the object class there's an equals method.

Remember when I used to say that default equals method compares the references of two variables?

This is the equals method I've been talking about.

There's also a two string method.

A harsh code method and a bunch of other methods.

Get class, notify, notify all that in overloads, the wait method three times, remember that overloading

means defining the same method more than once, but with different parameters.

And I commented these methods for simplicity.

OK, now what I want you to do is add another folder to your workspace.

So follow what I'm doing.

And grab the folder that corresponds to this path in the resources.

OK, before we continue, I want to repeat that the object class is the common ancestor of every class,

so every class inherits methods from the object class.

Inside may create a new object of the person, class, person, person is equal to a new person.

Zach.

Who's 27?

Now, from person noticed that we can automatically access so many methods, we can access an equals

method, a hash code method, a two string method, wait, notify get class.

But we didn't define any of these methods in the person class.

So where did they come from?

These methods came from the object class, because object is the common ancestor of every class, then

every class person is going to inherit all of its methods.

Here is equals.

Here's to string.

There is a code.

Get class, etc. This is inheritance.

Let's recap, a class can inherit properties from another class.

The object class is the common ancestor of every class, so every class inherits methods from the object

class.