A bundle of questions

Question

Hi,
I have several questions and hope that someone could help me.
Q.1
//in fileA.java
package p1;
public class A {
protected int i = 10;
public int getI(){return i;}
//in fileB.java
package p2;
import p1.*;
public class B extends p1.A
public void process(A a)
a.i = a.i*2;
public static void main(String [] args)
A a = new B();
B b = new B();
b.process(a);
System.out.println(a.getI());
Why the object b cannot access i ?
Q.2
public class Test {     
     public static void main(String [] args)
          int ia[][] = {{1,2}, null};
          int ij[][] = (int[][])ia.clone();
          System.out.println((ia==ij) + " ");
          System.out.println(ia[0]==ij[0] && ia[1]==ij[1]);
Why is the result: true, false. When should I use the object.clone()?
Q.3
public class Test {     
     public Test(){
          s1 = sM1("1");
     static String s1 = sM1("a");
     String s3 = sM1("2");
          s1 = sM1("3");
     static
          s1 = sM1("b");
     static String s2 = sM1("c");
     String s4 = sM1("4");
     public static void main(String [] args)
          Test it = new Test();
     private static String sM1(String s)
          System.out.println(s);
          return s;
Why the results are a b c 2 3 4 1? Why '1' will be the last one to be displayed?
Q.4
public class Test{     
public static void main(String [] args)
     int x = 4;
     int a [][][] = new int[x][x=3][x];
     System.out.println(a.length + " " + a[0].length + " " + a[0][0].length);
Why the answer is 4 3 3 ? Why the last 3rd dimension of array is 3?
Q.5
public class Test{     
public static void main(String [] args)
     String str = "111";
     boolean a[] = new boolean[1];
     if (a[0]) str = "222";
     System.out.println(str);
Why the a[0] represents false?
Thanks for your kind help.
gogo

Answer 1

A1.
It can!
A2.
The result is false, true.
A3.
When the class is loaded, all the static blocks and variables are initialized.
When you create a new Test object, then it first initialize all your non-static variables before it goes on with your constructor.
A4.
new int[4][3][3].. thats why
A5.
When you create e.g. a boolean array and don't initialize it, all elements will be false.