[SOLVED by RobinB]How to check if an object is not itself?

[wessles]

So, I have a problem. I need to loop through an arraylist of Zombies. The method that does this is inside of a Zombie object. I need to loop through all zombies except itself. So I tried this:

1   2

if(zombie != this)     Do crap

But that did not work. So what do I do? Googling has brought me nowhere.

[Phased]

This should work:

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if(!(zombie instanceof this)){ }

[Troncoso]

I don't see how that would work. But, I've never tried/seen it to know. (In reference to Phased's solution)

You could just give each zombie an id and check that.

Games published by our own members! Check 'em out!

[Phased]

I don't see how that would work. But, I've never tried/seen it to know. (In reference to Phased's solution)

You could just give each zombie an id and check that.

It does work, I checked it with my screen manager class.

for example

1	if(monster instanceof skeleton)

would return true if monster is a skeleton, and continue the if statement.

if you used

1	if(!(monster instanceof skeleton))

the if statement would only continue if the statement returned false, as the ! wants a non true value from

1	(monster instanceof skeleton)

[wessles]

Can you clean up that reply? You messed up the, er...  Idk.

[Phased]

I fixed it up just before you replied, it was fine until i refreshed it, guess the save didn't actually save.

[wessles]

Who said anything about monsters or skelibutts  ?
Well... I don't know how I would apply that. Can you put it in my terms? And also, I have the list of zombies ready, I just need to rule out the 1 in that list that is the zombie performing the check.

[wessles]

In other words, How could the zombie rule itself out of the list? It will still have all of the others of its type there. I think I should just give entities Ids. Should I? Sounds messy.

[Phased]

monsters and skeletons was just a easier example to explain the code.

Well, what is "this", you gave us a snippet of your code.

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if(!(zombie instanceof this)){ }

After re reading it a few times, I think i miss understood what you wanted, troncoso is right, you would need to have a unique ID for every single entity and compare the entitys ID with each other.

What are you trying to do that will compare a zombie with its self?

[ra4king]

First of all, why does the Zombie class have access to an ArrayList of Zombies? Secondly, if(zombie != this) should work as that checks for instance equality, which is exactly what you want.

"instanceof" is not the answer here, and was actually used incorrectly everywhere in this thread. You can only check "instanceof" with a class type, not an object. "instanceof this" or "instanceof anotherObject" will throw an error.

Games published by our own members! Check 'em out!

[wessles]

Yeah, like I said, not doing any of those, and I recall saying:

And also, I have the list of zombies ready, I just need to rule out the 1

Meaning, I can't use instanceof. I also said later:

I think I should just give entities Ids.

I already decided what to do.

1	Forum.getThread(30201.0).setSolved(true);

Gnight all!

[ra4king]

If giving the entities IDs is used only for this operation, then this is a pointless misuse of memory.

[Jimmt]

If giving the entities IDs is used only for this operation, then this is a pointless misuse of memory.

I have to agree. There's no reason for your Zombie class to have an ArrayList of Zombies. Then how does your horde work? Every Zombie instance has its own ArrayList of Zombies? That's startlingly inefficient.

[wessles]

NO! Oh my gosh you got this wrong... 
There is a parent class called world. They can access stuff from the parent by calling

1	getWorld()

. Then, they can do

1	getWorld().getZombies();

to get an arraylist of all zombutts. They don't all have a storage of that! They just use this:

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for(Zombie zombutt : getWorld().getZombies()) {     if(zombutt.getId() != this.getId() && zombutt instanceof Zombie)         Do crap; }

Like said, case closed.

[Jimmt]

Cycling through the same list/array in every single zombie instance is still a really bad idea, not to mention it doesn't make any sense (OOP wise). If you're going to do something to the zombies of the World do it either in the World class or make a separate class.

[wessles]

Well, what should I do? I am checking if any zombies are stuck inside each other...

[RobinB]

Look at this:
(This does not go inside the zombie class ofcourse)

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for(int zom = 0; zom < getWorld().getZombies().size(); zom++) {     for(int zom2 = zom+1; zom2 < getWorld().getZombies().size(); zom2++) {         Zombie zombie1 = getWorld().getZombies().get(zom);         Zombie zombie2 = getWorld().getZombies().get(zom2);         //Colission stuff    } }

* Why "zombutt instanceof Zombie"
if it has diffrent behaviour with colliding (e.g. none), dont put it in the same array.

[wessles]

Sorry, minecraft hardcore has given me a psychological complex where I insult such mobs monsters by ending their name with the shape of their face.

[wessles]

Oh, and thanks!

[RobinB]

Sorry, minecraft hardcore has given me a psychological complex where I insult such mobs monsters by ending their name with the shape of their face.

The name does not not bother me, but instanceof does
No probelm anyways.

[ReBirth]

If you're on OOP: world -> horde -> zombie where horde is holding zombie arraylist. There can be more than one horde in a world and more than one zombie in a horde.

If you're on the ES like Artemis, well, it's obvious that the corresponding system will fetch entire entities with zombie component and presents it as list. You just need to design that only ONE system that will need to fetch/process that list, ONCE in a loop if you can.

[wessles]

When did I mention a horde? They all have individual AI. They don't work together.

[Jimmt]

When did I mention a horde? They all have individual AI. They don't work together.

Either way, his point still holds...

[wessles]

Yeah, kinda how I check if enemies are close to the player as apposed to all enemies figuring it out . I already did that though... Mischeif...

[ra4king]

...Managed

[wessles]

What?

[ReBirth]

When did I mention a horde? They all have individual AI. They don't work together.

My point is that it's too mess to have a world which only single (you only have one right?) to handle all entities. Some entities share similarity that can make them to be grouped.

[wessles]

Wait, what are you responding to?
This?

What?

I was asking about this:

...Managed

Don't worry. I know what he was saying. Just wondering what he meant by ...Managed.

[meingrosserfreundjo]

Thats a pun refering to the Marauder's Map in Harry Potter which had to be wiped clean with the spell "Mischief Managed"

[wessles]

Oh yeah! Lol, it's been a bit since I've read Harry Potter.