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From: "Eric Sosman" <eric.sosman@1:261/38.remove-s5y-this>
Subject: Re: verbose sort
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Date: Thu, 02 Aug 2012 19:12:03 GMT
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  To: bob smith
From: Eric Sosman <esosman@ieee-dot-org.invalid>

On 8/2/2012 11:37 AM, bob smith wrote:
> I have some code that sorts a list like so:
>
> Vector<String> my_list = new Vector<String>();
>
>
>               Comparator<String> c = new Comparator<String>() {
>                       @Override
>                       public int compare(String object1, String object2) {
>                               if (object1 == null)
>                                       return -1;
>                               if (object2 == null)
>                                       return 1;
>                               object1 = object1.toLowerCase();
>                               object2 = object2.toLowerCase();
>                               return object1.compareTo(object2);
>                       };
>               };
>
> Collections.sort(my_list, c);
>
>
> This seems like a lot of code for such a common operation.  Is there a more
succinct way of doing this?

     Consider using compareToIgnoreCase().  Also, think about what
happens when two null's are compared: You should return zero rather than 
declaring one of them "less than" the other, because otherwise your comparator 
is inconsistent (you can have A<B, B<C, but C<A).

        public int compare(String s1, String s2) {
            if (s1 == null)
                return s2 == null ? 0 : -1;
            return s2 == null ? +1 : s1.compareToIgnoreCase(s2);
        }

--
Eric Sosman
esosman@ieee-dot-org.invalid

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