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Re: String[] , Arrays.asList , Collections.unmodifiableList

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On Fri, 09 May 2014 01:02:35 -0500, leif.roar@invalid.com (Leif Roar
Moldskred) wrote, quoted or indirectly quoted someone who said :

>Roedy Green <see_website@mindprod.com.invalid> wrote:
>> 
>> So what do people do?  They use Arrays.asList to convert to a List, an
>> java.util.Arrays$ArrayList.
>
>Return a clone of the internal array, not the array itself:
>
>public class NotBad {
>  private String[] myArray = ...;
>
>  public String[] getArray() {
>    if( myArray == null ) {
>      return null;
>    } else {
>      return (String[]) myArray.clone();
>    }
>  }
>
>>
>> But List still lets the user modify the field which in turn modify the
>> underlying array. We have gained nothing.
>
>The problem isn't that you're returning something the client can
>modify.  The problem is that you're giving the client backdoor access
>into this object's private state: if you just return your internal
>array any changes the client does to that array is a change in the
>state of /this/.  If you return a _copy_ of the internal array, or a
>list created from the internal array, any changes made to the return
>value by the client only affects the _client's_ state, not /this/'s.

I will add your idea to http://mindprod.com/arraylist.html#ARRAYASLIST
-- 
Roedy Green Canadian Mind Products http://mindprod.com
Culture is your operating system. 
~ Terence McKenna (born: 1946-11-16 died: 2000-04-03 at age: 53)

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String[] , Arrays.asList , Collections.unmodifiableList Roedy Green <see_website@mindprod.com.invalid> - 2014-05-08 21:30 -0700
  Re: String[] , Arrays.asList , Collections.unmodifiableList leif.roar@invalid.com (Leif Roar Moldskred) - 2014-05-09 01:02 -0500
    Re: String[] , Arrays.asList , Collections.unmodifiableList Roedy Green <see_website@mindprod.com.invalid> - 2014-05-09 09:25 -0700
      Re: String[] , Arrays.asList , Collections.unmodifiableList leif.roar@invalid.com (Leif Roar Moldskred) - 2014-05-09 12:45 -0500
  Re: String[] , Arrays.asList , Collections.unmodifiableList Stanimir Stamenkov <s7an10@netscape.net> - 2014-05-11 00:09 +0300

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