Re: Why must and must not be "final" ?

From:

"NeoGeoSNK" <ny1022@gmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

13 Nov 2006 21:46:49 -0800

Message-ID:

<1163483209.503484.62550@k70g2000cwa.googlegroups.com>

"Daniel Pitts =D0=B4=B5=C0=A3=BA
"

NeoGeoSNK wrote:

Hello,
I have two questions, why inner class can only access "final" argument
outside the inner class?
and why Java applet's init() method can't access any "final" fields?
  example:
  public class AppletGui extends JApplet {
                          .........

               final JTextField textvalue;

                         ..........

          public void init(){
                         ..........

                        textvalue = new JTextField(25); //this will
encounter a compiled time error "the final field AppletGui.textvalue
can not be assigned
          }
  }

any suggestions are appreciated. ^ ^
Thanks
NeoGeoSnk

Its purely to reenforce to the programmer what really is happening.

The value of your parameters/variables which are used in your
anonymouse class are copied at the time that the object is created
(they are actually hidden final fields, I believe). If you were to
change the value later, that would be more confusing than having to
know that they are just "final".

Thanks a lot,
and you mean this restriction only effective when a inner class is
anonymouse? and not for all inner class?