Re: return a Collection (Set or List)

From:
Lew <lew@lewscanon.com>
Newsgroups:
comp.lang.java.help
Date:
Tue, 13 May 2008 19:41:37 -0400
Message-ID:
<LJudnRdyttKsurfVnZ2dnUVZ_trinZ2d@comcast.com>
Eric Sosman wrote:

Roedy Green wrote:

On Tue, 13 May 2008 11:37:53 -0700, Mark Space
<markspace@sbc.global.net> wrote, quoted or indirectly quoted someone
who said :

Consider substituting two methods for this one. "getAsList" and
"getAsSet" Then the caller can indicate which type is desired and
always receive the correct type.


If it is always possible to get as List, why would you ever return
anything else? You can always use a List as a Set.


    String[] words = { "The", "thing", "about", "Sets",
        "is", "that", "each", "item", "is", "present",
        "once", "and", "once", "only." };
    List<String> list = new ArrayList<String>();
    Set<String> set = new HashSet<String>();
    for (String w : words) {
        list.add(w);
        set.add(w);
    }
    assert list.size() == words.length;
    assert set.size() == words.length; // BZZZZT!


Set <String> strangs = new ArrayList <String> (); // BZZZZT!

--
Lew

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