Family relations

Este ejercicio es ridículo. Todo irá bien hasta que llegas a la parte de "woman.husband / man.wife". Es simplemente contraproducente que te pidan hacer este tipo de cosas cuando no has adquirido todavía una base. No aporta nada para el usuario que está aprendiendo, no te ayuda a entender mejor lo que estás haciendo y tampoco tiene ninguna utilidad si no es con una explicación posterior.

I think writing "Man" and "man" is confusing.

Woman Class is a property of Man just like property of age and height in the class Man. The value (wife) serve as link to other class.

Got there by trial & error, 13 attempts. I am a total newbie and I am not sure I am actually learning rather than guessing. Can anyone else related? Or is the guessing part of the learning process?

What exactly is meant by "saving a reference to an object" after an object is defined? Having a hard time wrapping my head around the concept. Any help is appreciated.

woman.husband = man;
man.wife = woman;

Can someone help me understand why if I write the same as throws a NPE ?

man = woman.husband;
woman = man.wife;

Create 2 objects Man and Woman store "woman" reference in man.wife then store "man" reference in woman.husband

It was difficult, in case you have also struggled, please check below hints: => The first 2 tasks, you need to create 2 objects. One of the object's should be named as a Woman and the second one is called Man. A general rule how to create an object: ClassName objectname = new ClassName(); => The last 2 tasks, just think about very carefully about the hint that we have been given: woman.husband = man Good luck everyone!

Here are some explanations that may be of help: 1. A variable can be assigned to another variable, the same thing applies to an object reference. Meaning, an object reference can be assigned to another object reference. What is an object reference? Dog maxy = new Dog(); Here, maxy is an object reference. Now, maxy is already 'a variable that is referenced to a Dog object'. Since a variable can be assigned to another variable, the following is valid: Dog maxy = new Dog(); kikipaka = maxy; // here kikipaka is an object reference that refers to the sama object as maxy does. Be careful, if somehow your code is written like this: ********* kikipaka = maxy; Dog maxy = new Dog(); ********* The code won't compile because maxy the object reference has not yet been made. 2. The confusing '.' operator Please see the explanation about the cat. The code is as follow: ********** Person person; person = new Person(); person = null; Cat cat = new Cat(); cat.owner = new Person(); cat.owner.name = "William"; ********************** It's confusing because we assume that the '.' operator serves only to call something. But in fact, naming your variable with a dot '.' is valid. Meaning, naming your variable like String x.max = "Hello World"; is valid although you're not calling anything. Here you can see that the cat.owner does not serve to CALL, rather it is the NAME of the variable. Thus, a new object reference is made by writing *cat.owner = new Person();* It could also be written as *catOwner = new Person();* Try to change *woman.husband* to *womanHusband* and *man.wife* to *manWife*. Maybe you can understand better. p.s: I still have not yet understood the public Woman wife; and the public Man husband; I'm sure something I don't know is still lurking there, but I'll save it for later