shweta patiljadhav

I hav a doubt from

Mala Gupta's

book.

Suppose you have the following
definition of class Person:
class Person { private String name; Person(String newName) { name = newName; } public String getName() { return name; } public void setName(String val) { name = val; } }

what is the output of this code?
class Test { public static void swap(Person p1, Person p2) { Person temp = p1; p1 = p2; p2 = temp; } public static void main(String args[]) { Person person1 = new Person("John"); Person person2 = new Person("Paul"); System.out.println(person1.getName() + ":" + person2.getName()); swap(person1, person2); System.out.println(person1.getName() + ":" + person2.getName()); }



this is about referencing and output is John:Paul both times.

Please explain me how? it is been explained in book, I read it thrice, but bit worried that if this type of question comes in exam I will have to think a lot about such type of question ...if my concept is clear I will think else i won't.

Thanks,
Shweta

Hello,

In OCA Java SE7exam , questions from question paper are evenly distributed from all chapters? or some chapters have more weightage over others?

Thanks,
Shweta.

“How can you
declare a class Curtain in a package building so that it isn’t visible outside the
package building?”

and answer is package building; class Curtain {} because top level class can not be protected and private? being OCA candidate please explain me what is top-level class AND why it can't be protected if it can be default? I can understand it can't be private.

TIA

According to

Mala Gupta

book

if there are two packages, building and library,
book is base class in package library,

package building; import library.Book; class StoryBook extends Book { StoryBook() { Book book = new Book(); String v = book.author; book.modifyTemplate(); } }

Protected members of class Book are not
accessible in derived class StoryBook, if
accessed using a new object of class Book

derived class can inherit and access protected members of its base class, regardless
of the package in which it’s defined. A derived class in a separate package
can’t access protected members of its base class using reference variables.

and protected members are not accessible to unrelated classes in different package.

Please explain me first line.

Hi,

According to

Mala Gupta

book,
class AnnualExam { java.util.Date date1; java.sql.Date date2; }


will compile but

import java.util.Date; import java.sql.Date; class AnnualExam { }

won't complie....
please explain why?

Hello,

Do I need to give OCA before giving OCP exam? Which books are recommended for OCP? how to prepare for OCP ?


Thanks.

Thank you Sergej,

okay, but how String version is more specific than object version here?

TIA

Hi,

I ran this program on Netbeans and output is , String version, I don't understand why it is not object version?

Hello, What would be the out put of this code? please explain.


public class M { public void method(Object o){ System.out.println("Object Verion"); } public void method(String s){ System.out.println("String Version"); } public static void main(String args[]){ M q = new M(); q.method(null); } }

TIA

Hi ,

thank you very much! please give me an example code of making ArrayList of Double.

TIA

Please give me an example of ArrayList of double and floats....I am able to create one with String and StringBuilder only....
TIA

Thanks!

Hi,

in this code,class EJavaGuruStringBuilder { public static void main(String args[]) { StringBuilder ejg = new StringBuilder(10 + 2 + "SUN" + 4 + 5); ejg.append(ejg.delete(3, 6)); System.out.println(ejg); } }

what would be the output? if on StringBuilder methods are called from left to right here delete() is called first. and why it's output is not 12SUN4512S5?
Why it is appending out put of delete method twice?

output is 12S512S5 ?

TIA
Shweta

Hi Seregej,

I saw that OCP is not available for SE8 , and I don't have any study material for SE8, I liked Mala Gupta's book and it is available for SE7.....is there is huge difference between these 2? I have completed reading syllabus for SE7 now, will that help me if i want to prepare for SE8 now? I am thinking of taking one certification just to show that I know JAVA ...as I have changed country and my basic degree is not from this country where I live right now...and I am stay at home mum....

Please guide,
Thanks