What does def `self.function` name mean?

Question

Can anyone explain to me what the meaning of adding self to the method definition is? Is it similar to the this keyword in java?

Answer 1

When declaring a method, the self of the declaration is the declaring class/module, so effectively you are defining a class method. For the client, this works similar to a static method in java. The client would call the method on the class instead of an instance: MyClass.method

Here you can find some more details on class and instance methods.

EDIT: While the self keyword is akin to the this keyword in java, the effects of using self for class method declaration are similar to the effect of using the static keyword in java. The similarity is that static methods in java, like class methods in ruby are accessed using the class object iself instead of an instance of the class.

Please note that static does not stand for the opposite of dynamic. The choice of the name for this keyword is questionable (probably inherited from C) and rather should have been called perClass or similar to better reflect the meaning. The technical meaning is that all static members exist only once for each classloader.