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Re: java referencing question

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From	Jeff Higgins <jeff@invalid.invalid>
Newsgroups	comp.lang.java.programmer
Subject	Re: java referencing question
Date	Tue, 20 Jan 2015 10:03:12 -0500
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On 01/20/2015 09:17 AM, John wrote:
>
> I ran into a "strange" problem. If I understood the problem correctly, my summary is here:
>
> public class Team {
>      private Person teamLeader;
>
>      public Team(Person theLeader) {
>         teamLeader = theLeader;
>      }
>
>      public void doIt() {
>         teamLeader.speak();
>         ...
>      }
>
> }
>
>
> public class Demo {
>       public static void main(String[] args) {
>            Person leader = null;
>            Team dreamTeam = new Team(leader); //teamLeader inside dreamTeam is referencing an object which is also referenced by 'leader'. Right now, the object is null
>
>            leader = new Person(); //the object being referenced by leader is a good object now. So I thought teamLeader inside dreamTeam is referencing this good object too, since the two are referencing the same object
>            dreamTeam.doIt(); //crashes at teamLeader.speak() due to teamLeader is null -- I don't understand it. Please help.
>       }
> }
>
> The design is not good. I will change the design. Here I am puzzled by what I saw. Thank you.
>

4.3 Reference Types and Values
There are three kinds of reference types: class types (§8), interface 
types (§9), and array types (§10). Reference types may be parameterized 
(§4.5) with type arguments (§4.4).

4.3.1 Objects
An object is a class instance or an array.

The reference values (often just references) are pointers to these 
objects, and a special null reference, which refers to no object.

Thread

java referencing question John <xsli2@yahoo.com> - 2015-01-20 06:17 -0800
  Re: java referencing question Jeff Higgins <jeff@invalid.invalid> - 2015-01-20 10:03 -0500
  Re: java referencing question Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-01-20 10:23 -0500

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