How to initialize ArrayList

Question

I have a Very basic question. How do I need to type parrameters for ArrayList to use the code in BlueJ? I have a method as below.

public void requiresVaccination(int year, ArrayList<Cat>list)

I have created some cat objects cat1, cat2 and cat3.

I thought, I need to type 2012 for theyearand [cat1, cat2, cat3] for the ArrayList but obiusly I am wrong. Could anyone tell me what I need to do, please?

whirlwin · Accepted Answer · 2012-10-14 11:57:00Z

1

To invoke the method, pass the year together with a new ArrayList object.

Using double brace initialization, the code for the second argument becomes:

new ArrayList<Cat>() {{ add(cat1); add(cat2); add(cat3); }};

To call the method, use:

requiresVaccination(2012, new ArrayList<Cat>() {{ add(cat1); add(cat2); add(cat3); }});

I think this is the easiest way.

edited Oct 14, 2012 at 11:57

answered Oct 14, 2012 at 11:36

whirlwin

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OmniOwl · Accepted Answer · 2012-10-14 11:34:44Z

0

You have to give the method a list of Cat Objects, you can't do what you are suggesting.

answered Oct 14, 2012 at 11:34

OmniOwl

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OmniOwl Over a year ago

Hmm, okay then. Will change it.

Bahram · Accepted Answer · 2012-10-14 11:44:57Z

0

I think it is possible to use a signature like this

public void requiresVaccination(int year, Cat... list)

therefore you can call your methode something like this

 requiresVaccination(2010, cat1, cat2, cat3);

and inside function it is possible to behave with list like an array of Cat (Cat[])

answered Oct 14, 2012 at 11:44

Bahram

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user1721548 Over a year ago

Sorry I am confused still so if I want to test my code. I need to create method call is that right? Then how do I call my method? and how can I use a debugger in BlueJ.

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