INNER CLASS

[sheri]

Which are a part of a correct inner class declaration or a combined declaration and instance initialization

A. private MyInner {
B. new SimpleInterface() {
C. new ComplexInterface(x) {
D. private final abstact class C
E. new ComplexClass() implements SimpleInterface
MY ANS ARE:A,B,C
NOT SURE IF OPTION C IS CORRECT,PLS CORRECT ME IF I AM WRONG

2: What snippet can be a part of a declaration of an inner class: (select all)
A. private MyInner {
B. new myInner() extends OtherClass {
C. static class MyInner {
D. abstract class MyInner {
MY ANS ARE:A,C,D
Which are valid declarations :
a. private class A
b. class X extends Y { // Note the {
ANS ARE:A,B
I AM APPEARING FOR THE EXAM BY THIS SATURDAY
HELP PLS
THANX
SHERIN

[Mapraputa Is]

Hi sheri!
If �combined declaration and instance initialization� means that class is anonimous (and I think so)
than
C) new ComplexInterface(x) {
is incorrect, because anonimous inner classes cannot have a constructor, which could take parameter x.
If option C were coded as
C) new ComplexInterface() {
- it would be correct

[Anonymous]

Hi sheri;
Here is my answers:
Which are a part of a correct inner class declaration or a combined declaration and instance initialization
A. private MyInner {
B. new SimpleInterface() {
C. new ComplexInterface(x) {
D. private final abstact class C
E. new ComplexClass() implements SimpleInterface
Answers: B,C
A is incorrect since it misses the keyword class in the declaration.
2: What snippet can be a part of a declaration of an inner class: (select all)
A. private MyInner {
B. new myInner() extends OtherClass {
C. static class MyInner {
D. abstract class MyInner {
Answers: C,D

Thanks,
Erin

[geetha]

Originally posted by Mapraputa Is:
Hi sheri!
If �combined declaration and instance initialization� means that class is anonimous (and I think so)
than
C) new ComplexInterface(x) {
is incorrect, because anonimous inner classes cannot have a constructor, which could take parameter x.
If option C were coded as
C) new ComplexInterface() {
- it would be correct

Hi,
if the annonymous class is extending from any class which has a constructor then the ans C would be correct.here he didn't mention that complexinterface is an interface or a class.ofcourse there is a clue that it can be an interface but we are not sure whether that is extending from class or interface in which case I would say C is also correct ans.
geetha

[ramani2020]

hi geetha,
But anonymous classes, by definition, dont have a constructor or a name.
If the class extends another class which has a constructor, the inner class is not anonymous ..am I right? or am I missing something?
could you give an example ?
or,could you tell me what modifications are to be made to convert the foll into an anonymous class like you said, extending from class father, and without a name..

    import java.applet.Applet;
    public class ParentClass extends Applet
    {   
        final int d = 10;
        public void init()
{ 
            class ChildClass extends father // this class
            {                               //doesnt have to
                                            //extend father
                                            // to work 
             
    new father(d).method(d);   
    }
        }
    } // end of ParentClass
    class father
    {   
        static int y;
father(int x)
{ 
y = x;
}
void method(int x)
{
System.out.println("integer in inner class is: " +x);
}

     }

thanks in advance,
Ramani.

[Jane Griscti]

Hi Ramani,
I played with your code and think this is an example of using an anonymous class (please let me know if I'm wrong).
I changed the original to use main() instead of Applet and I had to put a call in the 'father' constructor to access method() (is there a way to directly invoke a parent method from an Anonymous class? I could not find any code examples.)

class TestAnonymous
 {    
      public static void main(String[] args)
     {      
         final int d = 10;        
         father f = new father(d);       // uses original method
         father fAnon = new father(d){   // uses new method      
           void method(int x){     
             System.out.println("Anonymous: " + x);       
           }
         };
     }
 
 } // end of ParentClass
 
 class father
 {   
     static int y;
     
     father(int x){ 
         y = x;
         this.method(y);
     }
     
     void method(int x){
       System.out.println("integer in inner class is: " +x);
     }     
  }  
The output is:
integer in inner class is: 10
Anonymous: 10