Classes create objects
Objects are instances of classes.
Classes are kind of blue prints for the concrete objects. Every time a concrete
object (such as the String
"one string", the String
"another string", the
"yet another string", and so on …) is created:
We say that the class is instantiated: an object is created from it.
What does that mean?
Classes have a bunch of characteristics, but most importantly, every class defines a number of methods, which are specific to this type of thing (e.g. a String).
Now, every time a new object is created (“instantiated”) from this class this new object get (“inherits”) all of these methods.
Objects inherit methods from their classes.
That’s right. Objects have their own methods attached to them.
We’ll explain more about methods that belong to objects in the next chapter. And you’ll see how you can define methods to your own classes, so they’re then available on your objects when we start defining our first, own class.
But for now we can already point out that all concrete Strings that you use in your code will all have the same methods defined (attached to them) … because they’re all created (instantiated) from the the same class.
You can have a look at all the methods that the class
String defines on
Ruby’s documentation page for this
Let’s see how we can use these methods.