interface problem

[Mohit G Gupta]

SCJP1.6 JAVA 6 CERTIFICATION Guide-310-065
by Katherine Sierra (Author), Bert Bates (Author)

  
1. public class Electronic implements Device
{ public void doIt() { } }
2.
3. abstract class Phone1 extends Electronic { }
4.
5. abstract class Phone2 extends Electronic 
{ public void doIt(int x) { } }
6.
7. class Phone3 extends Electronic implements Device
{ public void doStuff() { } }
8.
9. interface Device { public void doIt(); }

  

how can a class change parameter type of a method or this is function overriding

[Prasad Kharkar]

this is not function overriding
this is called as function overloading
How to know whether a method is overloading method : -

The name of method is same as that of another method

The argument list must be different in overloading

The return can change but if only return type is changed, that is not a legal overload

Overriding : -

The method arguments list must be same

The return type should be same

here in this case
the doIt method in class Electronic is overriding the doIT method in interface device
and the doIt(int i ) method is overloading the method doIt in interface device
hope this helps
happy coding

[Roberto Perillo]

Let's continue this discussion here.