I got confused while stuyding java in deep with the core concept.
what i have studied is, if you have interface
public interface interfaceconcept {
public void heyyou(String s);
public abstract void nono(String s);
public void kolk(int i);
}
and you have a class which implements the interface then you have to write the body of all the methods
public class implementation implements interfaceconcept{
@Override
public void heyyou(String s) {
// TODO Auto-generated method stub
}
@Override
public void nono(String s) {
// TODO Auto-generated method stub
}
@Override
public void kolk(int i) {
// TODO Auto-generated method stub
}
}
if you dont want to write the methods you can use abstract class
Now i was studing about comparator, and while inpecting its class i found it is an interface
public interface Comparator<T> {
//
}
now it implemented it in another class, firstly it gave me an error saying.
The type Order must implement the inherited abstract method Comparator.compare(Order, Order)
i have added all the method by clicking add unimplemented method and remove all but one.
but when i compiled it, it simply compiled why? am i not supppose to add all the unimplemented methods of comparator interface as per the rules of java?
Also one of its method in comparator class is
default Comparator<T> reversed() {
return Collections.reverseOrder(this);
}
what is the point if you have written the implementation of one method in interface itself? you cant write any body of the method, if i m correct.
public class Order implements Comparator<Order>{
@Override
public int compare(Order o1, Order o2) {
// TODO Auto-generated method stub
return 0;
}
}
