?
Solved

True & flase Statements

Posted on 2002-04-17
1
Medium Priority
?
236 Views
Last Modified: 2010-03-31
hi..i need to know if the following sentences are true or false..and why? simple explanation plz

1) subclass variables should be defind as private to hide them from other subclasses. (        )
2) main method can't directly access any non static method and varibales,but using the instance of the class it can.!!!!!!


my comments or concerns..for the following :
1) i guess it should be true.. cuz of the encapsulation.. am i right..or it's not forced to be private .. only it's a better way to hide variables.. ?!?!!/ i'm not sure.just giving what i know..and waiting for ur answer

2) but why other static methods can't use instance of the class?!?!!?

hope i've made myself clear enough to get ur answers..
i'll be waiting..
0
Comment
Question by:ms_lost
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 86

Accepted Solution

by:
CEHJ earned 40 total points
ID: 6949262
1. True. As you say 'cuz of the encapsulation'. This is true generally of any class, not just subclasses. This prevents client classes from directly accessing the fields directly. Using accessor methods (get/set) provides a useful layer of indirection, such that the method may do things other than simple assignments (this.someProp = someProp).
2. True. 'but why other static methods can't use instance of the class?!?!!?' They can:

zclass StaticAccess {

  /**
   * Note that this variable must be declared 'static' to be accessible from
   * accessInstance() or any other static method
  */
  static StaticAccess instance;

  public static void accessInstance() {
    instance.printMessage();
  }
     
  public void printMessage(){
    System.out.println("In instance method");
  }

  public static void main(String[] args) {
    // Comment the next line out. What will the result be?
    instance = new StaticAccess();
    StaticAccess.accessInstance();
  }
}
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Are you developing a Java application and want to create Excel Spreadsheets? You have come to the right place, this article will describe how you can create Excel Spreadsheets from a Java Application. For the purposes of this article, I will be u…
Introduction This article is the second of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers the basic installation and configuration of the test automation tools used by…
Viewers learn about the scanner class in this video and are introduced to receiving user input for their programs. Additionally, objects, conditional statements, and loops are used to help reinforce the concepts. Introduce Scanner class: Importing…
Viewers will learn about arithmetic and Boolean expressions in Java and the logical operators used to create Boolean expressions. We will cover the symbols used for arithmetic expressions and define each logical operator and how to use them in Boole…
Suggested Courses
Course of the Month9 days, 2 hours left to enroll

764 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question