Core Java Interview Questions, Answers for Freshers and Experienced asked in various Company Job Interviews

Core Java Interview Questions

Questions Answers Views Company eMail

printstream class method println() is calling using System class and its static object out .how it is explain any one in detail with example ?

TCS,

1 5389

whats the purposr of using serialization?

6 9692

how to one war file class to another war file class?

2076

suppose in a class there is a code like this: { Set hs=new Hashset(); hs.add(new Emp("kathy",1000)); hs.add(new Emp("kathy",2000)); } how can u avoid the above code in your class as set won't allow duplicate objects?

3 6623

what is meant by UP& DOWN casting in java?

6 14477

how can we import the user defined package without classpath?

CSC, Infosys,

1 7766

Write a java program to find the route that connects between Red and Green Cells. General Rules for traversal 1. You can traverse from one cell to another vertically, horizontally or diagonally. 2. You cannot traverse through Black cells. 3. There should be only one Red and Green cell and at least one of each should be present. Otherwise the array is invalid. 4. You cannot revisit a cell that you have already traversed. 5. The maze need not be in the same as given in the above example

2601

For ease of programming you can consider the maze as a 2D array with colors represented by below integer and characters (in capital letters). • B - Black • W -White • G- Green • R- Red R B W B W W W W W W B W B B W W W W W W W B W B W W W B W W W W B B W W W B W W W B W W B B B B W B W B W W B W W W B W W W B B B W W B W W W B W W B W B W W W B W B W W W W B B W W W W B W W W W W G Shortest Route Problem: • Solution that finds the shortest Route between Red and Green  White will have 1 Weight.  Red and Green carry no weights.  Shortest path is the path with less weight when you add up the weights in the path.

2017

what is j2se

3 6375

we have two threads..both the threads are reading the data.. is there any need of synchronization there?...justify it?

IBM,

4 8353

what is unreachable code problem in multiple catch statements

3 6591

where lives in jvm

5 8931

What is "Java Native Interface" and how to use it?

IBM,

1 6004

What is the diff. b/w Interfaces & Abstract class?

Ericsson,

6 10466

Which of these methods belong to Thread & Object class? join, yield, sleep, wait, notify

Ericsson,

3 10140

Post New Core Java Questions

Un-Answered Questions { Core Java }

In a class implementing an interface, can we change the value of any variable defined in the interface?

1085

How do you decide when to use arraylist and linkedlist?

991

Give any two differences between C++ and java.

1146

What do you mean by global variable?

953

How we can skip finally block of exception even if some exception occurs in the exception block in java?

948

What are advantages and disadvantages of OOPs?

1140

I want my class to be developed in such a way that no other class (even derived class) can create its objects. How can I do so?

983

Write java program to reverse string without using api?

1053

Explain covariant method overriding in java.

1106

What is the method in java?

1101

Can an integer be a string?

1065

What is an object in java?

1036

What is the use of bufferedreader?

996

What is the importance of finally block in exception handling?

1031

What is the use of static class?

1190

For More Un-Answered { Core Java } Questions Click Here