Re: create an ArrayList + add a first element and return the List in ONE statement possible ?

From:
Lew <noone@lewscanon.com>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 27 Jan 2011 15:17:50 -0500
Message-ID:
<ihsjon$hlb$1@news.albasani.net>
Robin Wenger wrote:

As the subject said I wonder whether there is really no one-liner for creating an ArrayList + assign of the first element +
return the new list. I have expected the following to work in such a way but it does NOT work:

   Object77 oneObject = new Object77();
   ArrayList<Object77> lObj = new ArrayList<Object77>(oneObject);

The following returns a boolean and not the desired List:

   boolean success = (new ArrayListObject77>()).add(oneObject);

Any other ideas?
Or do I really have to split this simple operation into separate statements?


Why is it a problem to split it into separate statements?

Ian Pilcher wrote:

There are lots of ways, including:

     ArrayList<Object77> lObj = new ArrayList<Object77>(
             Collections.singleton(new Object77()));


The declared type should probably be 'List<Object77>'.

The Javadocs might also lead one to:

  List <Object77> lObj = new ArrayList <Object77>
   ( Arrays.asList( new Object77() ));

or, if you aren't particular about the implementation:

  List <Object77> lObj = Arrays.asList( new Object77() );

which saves a copy operation.

As Ian said, there are many ways. Know thy API. The study of the collections
types is especially rewarding.

http://download.oracle.com/javase/tutorial/collections/index.html

--
Lew
Ceci n'est pas une pipe.

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