File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes Programmer Certification (SCJP/OCPJP) and the fly likes K&B LearnKey Exam Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Certification » Programmer Certification (SCJP/OCPJP)
Bookmark "K&B LearnKey Exam" Watch "K&B LearnKey Exam" New topic

K&B LearnKey Exam

Vyas Sanzgiri
Ranch Hand

Joined: Jun 16, 2007
Posts: 686

  • is-a relationships always rely on inheritance
  • is-a relationships always require at least two class types
  • is-a relationships always rely on polymorphism

  • I do not understand point 2 and 3. Please explain

    ===Vyas Sanzgiri===
    My Blog
    Amey Chitre

    Joined: Mar 18, 2009
    Posts: 9
    Is-A requires two class types - this can be explained on the basis of 1st point Inheritance means class A extends B means Class A IS-A B
    Also interfaces are like abstract classes interface A implements B ie it requires atleast two class types two show the IS-A relationship

    Use of Inheritance means code reuse or use polymorphism thats why IS-A relys on polymorphism

    would really appreciate some more people comment on this

    Amey Chitre

    Ankit Garg

    Joined: Aug 03, 2008
    Posts: 9465

    Well Is-A relationship doesn't require two classes always. When you extend an interface from another or implement an interface in a class, then there is none and 1 class involved respectively...

    SCJP 6 | SCWCD 5 | Javaranch SCJP FAQ | SCWCD Links
    Vyas Sanzgiri
    Ranch Hand

    Joined: Jun 16, 2007
    Posts: 686

    Which proves that there are mistakes in the K&B exam. I found at least 3-4 mistakes per exam. Please be careful while reviewing.

    Another disaster is in the MusicPlayer class the jar given in the question is mp.jar but the answers have cp.jar as the correct answer!!
    I agree. Here's the link:
    subject: K&B LearnKey Exam
    It's not a secret anymore!