Core Java Interview Questions
Questions Answers Views Company eMail

What is garbage collection in Java, and how can it be used ?

Accenture, HCL, Infosys, TCS, Wipro, Sara, SITS,

32 57819

Differentiate Vector and ArrayList?

Wipro, Max Telecom,

6 8204

Differentiate constructor and a method and how are it be used?

Wipro,

7 8689




What is an abstract class?

DBS, Wipro,

7 7506

How can final class be used?

Accenture, Wipro,

5 9418

By what default value is an object reference declared as an instance variable?

Wipro,

1 10740

Java support what type of parameter passing ?

Wipro,

7 12051

Explain the term serialization?

Wipro,

10 9902




Is there is any error if you have multiple main methods in the same class?

Infosys, Wipro,

10 11235

What is Overriding and how can it be used?

Wipro, Consagous,

7 13657

Explain pass by reference and pass by value?

IBM, Wipro,

8 12061

In which way does a Primitive data type is passed ?

Sun Microsystems,

5 7823

What happens when a main method is declared as private?

DELL, Infosys, L&T, Sun Microsystems,

22 36983

Is there any need to import java.lang package?

Sun Microsystems,

13 15285

What is UNICODE?

3 4562


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Un-Answered Questions { Core Java }

Which of the following is not an isolation level in the JDBC

941


If goto and const is reserve words than why it is not work in java?

883


What is the main functionality of the remote reference layer?

748


what are Hostile Applets?

896


Hi.... I applied for the post of scientific officer/Engineer-SB(Programmer).Please post the syllabus and sample papers.

877






What is your platform?s default character encoding and how to know this?

1082


3.2 Consider the following class: public class Point { protected int x, y; public Point(int xx, int yy) { x = xx; y = yy; } public Point() { this(0, 0); } public int getx() { return x; } public int gety() { return y; } public String toString() { return "("+x+", "+y+")"; } } Say you wanted to define a rectangle class that stored its top left corner and its height and width as fields. 3.2.1 Why would it be wrong to make Rectangle inherit from Point (where in fact it would inherit the x and y coordinates for its top left corner and you could just add the height and width as additional fields)? (1) 8 Now consider the following skeleton of the Rectangle class: public class Rectangle { private Point topLeft; private int height, width; public Rectangle(Point tl, int h, int w) { topLeft = tl; height = h; width = w; } public Rectangle() { this(new Point(), 0, 0); } // methods come here } 3.2.2 Explain the no-argument constructor of the Rectangle class given above. 3.2.3 Write methods for the Rectangle class to do the following: • a toString() method that returns a string of the format "top left = (x, y); height = h; width = w " where x, y, h and w are the appropriate integer values. • an above() method that tests whether one rectangle is completely above another (i.e. all y values of the one rectangle are greater than all y values of the other). For example, with the following declarations Rectangle r1 = new Rectangle(); Rectangle r2 = new Rectangle(new Point(2,2), 1, 4); the expression r2.above(r1) should give true, and r2.above (r2) should give false. (You can assume that the height of a rectangle is never negative.) (2) (5)

1136


when a request is generated from apache tomcat 5.5 and goes to oracle 10g or mysql,,, how the oracle or mysql reads the request as apache is a web server and oracle 10g is application server? when the oracle 10g provides response, how the apche tomcat reads it???

996


placement papaers of spring computing technology

355


1.IN CASE OF DYNAMIC METHOD DISPATCH WHY WE USE REFERENCE VARIABLE,WE CAN USE THE DIFFERENT DEFINED OBJECT DIRECTLY TO ACCESS THE DATA MEMBER AND MEMBER FUNCTION OF THAT RESPECTIVE CLASS?WHAT IS THE MAIN FUNCTION OF "REFERENCE VARIABLE" HERE?

2499


how to write a program for sending mails between client and server

935


Q1.A. Write note on “The class path Environment Variable”? B. Which are different kinds of source code? Q2.A. How to create an interface? B. Why convert an applet to an application? Q3.A. How to use Media tracker Class. B. How to use string tokenizer class. Q4 A. Explain the overview of UDP messaging. B. Difference between SQL Exception class and SQL Warning class. Q5. A. How to create com object in Java? B. Write short notes on “The properties class” Q6. A. When object is created and destroyed? B. Explain the JDB in depth & command line. C. Write short notes on Web Sites.

5839


Tell me the Importent classes in net package?

971


Howto get an object that will perform date & time calculations then format it for output in some different locales with different date style.can ne1 tel me the answer of this question.pls

842


How to Sort Strings which are given in List and display in ascending order without using java api.

2769