Java Struct

[akl]

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.applet.*;



public class sock extends Applet {

    O_figuros Obj=new O_figuros();
 
public void init(){
   
  
   }
  

public class  subC{
      public int[][] matrix=new int[3][3]; 
}

public class subB {
      public subC[] turn =new subC[4];
}


public class O_figuros{
       subB[] figure= new subB[4];
       private int[][] arrowFig1=new int[][]{ {0,2,0},{0,2,0}, {0,2,0}};
       public O_figuros() {
        figure[0].turn[0].matrix=arrowFig1; //Exception in thread "main" java.lang.NullPointerException
        }
          
}
}

What is wrong with this structure ? why "figure[0].turn[0].matrix=arrowFig1" can't save value?

[sunde887]

Your bracketing is very wrong. Each open bracket, or parentheses should have a closing one.

[akl]

Your bracketing is very wrong. Each open bracket, or parentheses should have a closing one.

If launching program, I have this error.

appletviewer h.html
java.lang.NullPointerException
at sock$O_figuros.<init>(sock.java:32)
at sock.<init>(sock.java:11)
at sun.reflect.NativeConstructorAccessorImpl.newInsta nce0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInsta nce(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newI nstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Construc tor.java:513)
at java.lang.Class.newInstance0(Class.java:355)
at java.lang.Class.newInstance(Class.java:308)
at sun.applet.AppletPanel.createApplet(AppletPanel.ja va:785)
at sun.applet.AppletPanel.runLoader(AppletPanel.java: 714)
at sun.applet.AppletPanel.run(AppletPanel.java:368)
at java.lang.Thread.run(Thread.java:662)

[sunde887]

Try printing the variables, the one that prints 'null' hasn't been initialized properly. As it stands your code is a bit confusing, you should considering thinking it over and try making it easier to understand.

[Norm]

You define an array.
Where do you put any values in the array?