Arraylist of objects

General Discussion Other

enonod

in General Discussion • Other • 1 year ago

Using version 2

I have a class 'thing a'.

I need a class 'container b' which consists of a varying number of 'thing a's. A class, simply so I can use the mouse to discover which 'thing a' within 'container b'

I have a fixed number of 'container b's

I think I need a Array of 'container b's so I can reference... [b,a]

When the mouse is over a 'thing a' I need the number of 'thing a' within 'container b' and also which 'container b'.

Should I be looking at an ArrayList of 'container b's?

Is this a simple 2D array of objects?

Thank you

Replies(5)

Chrisir

Re: Arraylist of objects

1 year ago

So you got a within b.

But b within c (List of b).

Is this necessary? Don't we have a within b?

When not:

When number of bs is fixed:

use Array c of b;

b is an ArrayList of as.

You can for loop and then detect a and b.

2D Array is Not enough since the number of a's in every b can differ.

But maybe you think Too Complicated? What do you want really?

enonod

Re: Arraylist of objects

1 year ago

Thanks for replying. I was trying to keep it general.

Let us say that I have a single Map.

That Map contains countries, the number of which is fixed but could be say 30.

Each country can have unknown number of counties or areas but always begins with one area full size.

New smaller areas can be created by dividing larger areas.

Areas can also be amalgamated into larger areas but of course only adjacent ones.

Each area has a population, which of course grows or shrinks according to the above.

I want to keep track of each country and its areas and their populations and refer to each.

i.e.

Country A has areas 1,2,3,4 populations 200, 350,100, 500

Country B has areas 1,2 populations 300, 700

when B [2] is split into [2] and [3] the population of 700 splits but according to the relevant size of [2] & [3]

There are other attributes to each country and area, hence these are classes.

Perhaps this is clearer.

enonod

Re: Arraylist of objects

1 year ago

I think I need a fixed array of countries and each item in the array is an ArrayList of areas/counties (objects).

What I cannot see is how to declare the two items.

I have read a great many similar answers for Array of Arraylists but they 'seem' to me to be declaring ArrayLists of ArrayLists, or I am misreading the code because the author refers ambiguously to an array of ArrayLists by using the 'name' ArrayList[]

Any help please?

Chrisir

AW: [WatchList] Arraylist of objects

1 year ago - via EMail-to-forum

does this help?

http://forum.processing.org/topic/array-of-arraylist-and-save-arraylist#25080000001309175

enonod

Re: Arraylist of objects

1 year ago

Yes! Thank you.

Top Reply