Object lifetime

talking theoretically for the rest of the code, I suppose

Once you delete all references to an object, the object ceases to exist. And if you create another object with the same characteristics, it would no longer be the same but a new one, in a new memory space. And if you talk about the reference it still exists but it points to another object or null. And when creating a new object using the same reference, the reference still points to another object with the same characteristics.

Sos lo máximo. Gracias por explicar.

They talk about what happends at runtime. If you set to null all references to a Cat object, like this:

Cat cat = new Cat();
lastCatReference = cat;
...
cat = null;
lastCatReference = null;

you just lost the object.

An object variable would hold a reference to the object, so the object would not be a candidate for GC. If you mean store the object reference string i.e. @234234234, and then let the GC collect the object, then re-animate an object using @234234234 then still no, because the GC removes the reference from the heap when it removes the object, so there is nothing on the heap matching @234234234

What..... you are cheating ? I have 237 matter at this point. Solve your exercises that is the point of this training :D don't be lazy, if not I will come to UK and steal your job. 🤣😂

Literally cheating lol, everyone else worked much harder to get here than you haha

No, the reference itself is invisible to you and you assign it's value to the variable you created. In the example you provided the program copied the same reference and stored it in a new variable. A reference is a value corresponding to a specific cell in computer's memory where the object was created, you can have a lot of copies of that value but if you change it, decrease or increase it, it would point to a different slot in memory ergo not the same object anymore. Since a reference is a binary value that points to a specific object, once you loose the reference by overriding your variable with a different value, it becomes impossible for you to access that object since you have no idea where in the memory it actually is. That is also the reason why you can't create a reference on your own, you wouldn't even know where to start. To create an analogy imagine the memory as a junkyard like the one in Inside Out movie. Each time you create an object in Java you tie a rope to it and throw it down there to store it. You don't really know where it is but you don't care much since you have a rope you can use to pull it out if you need the object for something. Each variable would be a person standing on the edge, holding that specific rope. There of course can be a couple people holding the same rope. You can tell them to move around and grab different ropes but if it so happens that there's no one holding a specific rope anymore, it falls down. No variable is able to access it, good luck going into the junkyard yourself to find the object and the corresponding rope, and bringing it back up for a variable to grab. Hope that helps :)

It is the best explanation of references I've ever seen!!! Thanks Wojciech!🤟

I would have never thought I'd have to watch Disney movies to learn Java :-D But thanks Wojciech, that explanation really helped!

Good explanation.👍👍