Re: how do I merg two collections?

From:
Eric Sosman <esosman@comcast-dot-net.invalid>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 05 Jan 2015 11:52:59 -0500
Message-ID:
<m8efgj$c0k$1@dont-email.me>
On 1/5/2015 11:38 AM, BOB wrote:

On Monday, January 5, 2015 6:57:22 AM UTC-7, Eric Sosman wrote:

On 1/5/2015 1:55 AM, Brian O'Brien wrote:

I have two collections and I want to create a third Collection that is the union of the two collecions.

//psuedo code


      How do yuo pronuonce "psuedo?" :)

Collection<String> a = "1","a", "2", "b";
Collection<String> b = "3", "a, "4", "b";
Collection<String> c = a + b;
// would produce..
"1", "a" , "2", "b", "3", "4"

Is there a collection method that does this?

Or must I iterate through the one of the sets and add to the other if it does not 'contain' the object?


      If you want c to contain no duplicated elements and you don't
care about their "order," use a Set:

    c = new HashSet<String>(a).addAll(b);

      If you want to keep the a's and/or b's in their original order
(or in any defined order), or if you want to preserve duplicate a's and
duplicate b's (while eliminating b's that duplicate a's), please
describe in more detail what you're trying to accomplish.


Order in not important, what is important is that the Collection NOT contain any duplicates and remains a Collection.


     Okay, use a Set. I've shown a HashSet, which is probably the
"go to" flavor for general-purpose use, but other kinds of Set are
also available if you want their special capabilities.

--
esosman@comcast-dot-net.invalid
"Don't be afraid of work. Make work afraid of you." -- TLM

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