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interface again

Neha Sawant
Ranch Hand

Joined: Oct 11, 2001
Posts: 204

this code is complaining that Observer interface not found in class B1.
what is my mistake here.
Anyone please
class A implements Runnable{
public void run(){}}
class B1 extends A implements Observer {
public static void main(String args[]){
A a = new A() ;
B1 b = new B1();
Object o=a; Runnable r = o;
Object o=a; Runnable r = (Runnable)o;
//Object o=a; Observer ob = (Observer)o;
Object o=b; Observer o2 = o;
Object o=b; Runnable r = (Runnable)b;
Object o=b; Observer o2 =(Observer)o;
Observer o=new B();

Michael Ernest
High Plains Drifter

Joined: Oct 25, 2000
Posts: 7292

Did you import the package they're in (java.util)?
Michael Ernest, co-author of: The Complete Java 2 Certification Study Guide

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Fei Ng
Ranch Hand

Joined: Aug 26, 2000
Posts: 1242
import java.util.*;
do you have that?
Neha Sawant
Ranch Hand

Joined: Oct 11, 2001
Posts: 204
thanx Micheal And FEING
That was my mistake.
Will we be tested on these also.
i.e. do we have to point out whether import statement is missing
I agree. Here's the link:
subject: interface again
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