Convert HasMap to Arraylist ??

[Niara Bhonde]

Hi All,

Could anyone give me an example of how to convert a HashMap to an Arraylist?

I have a method which returns a Map of userID's and userNames.
I need to convert this Map to an ArrayList so I can use the size, and get methods on it.

Thanks in advance!

Niara.

[Wirianto Djunaidi]

Niara,

Can you elaborate more on what you are trying to do?
There are already size() and get() methods on Map.

-DJ

[Jesper de Jong]

This question does not seem to be about the SCJP exam. I am moving this to the Java in General (Beginner) forum. Please continue there.

[Vishal Matere]

Check following methos

1.HashMap.entrySet()
2.HashMap.keySet()
3.HashMap.Values()

[Campbell Ritchie]

You don't need to convert the Map to get size() or get(). Maps and Lists are totally different. If you really want to iterate through the Map use the entrySet() method which gives a Set you can iterate through.

Other people have already told you this.

[Javier Elizondo]

Try this:

Map aMap = new HashMap() ;
aList = new ArrayList(aMap.values ());

[Campbell Ritchie]

That is a very good suggestion, Javier; it only needs a type declaration which would be List<E>.
Please keep helping, but we usually try not to post on such an old topic; we have a badly-named FAQ about that.

Please keep posting, but watch the dates on the previous posts.

CR