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

Core Java Interview Questions

Questions Answers Views Company eMail

my method "abc" return array of interface "xyz" and "pqr" is abstract class implements abc and class "jkl" extends pqr My problem 1) when i call abc it retrun array xyz how can i do this hint xyz refer_xyz = new jkl(); but i can't create array. 2)I want to access method of jkl using reference of xyz??

1 3917

why interaction with server using javascript is difficult

1 3858

StringBuilder s = new StringBuilder("Hello Mom");s.append(",I mean,Mother"); Response.Write(s.ToString()); String s = "Hello Mom"; s+ = ",I mean Mom"; Response.Write(s); Which is faster ? which uses the most memory?

HCL,

6 8976

I have one Shopping cart application, i that i have selected some items, while clicking submit button by mistake i have clicked twice or trice, that time items are selected twice or trice. Actually i want only one copy of items but its selected twice or trice. So how can we avoid this problem?

Honeywell,

2 6847

How Vector class is synchronized,How to build user defined class as synchronized?

2058

What is difference between abstract class & final class

7 27052

Hai all I want to print given array in reverse order Ex: int a[]={1,2,3,4,5};display this array in reverse order.

4 6087

what is the output ? Math.floor(-2.1) a)2 b)-2 c)-3.0 d)0

Accenture,

4 13901

How to find the size of an array a)array.length() b)array.length c)array.size() d)array.size

Accenture,

6 10977

what is the Yield() method used in threads?

Accenture,

4 8567

System.out.println(101/14) what is the output? a)6 b)14 c)7.14 d)0

Accenture,

8 10671

when a servlet sends request for first time it uses the follwing methods a)init b)doget() c)dopost() d)service

Accenture,

4 7515

What is Hash Code in Java?

Cognizant,

6 15996

What are uses of Hash Code?

Cognizant,

2 7465

I have 100 records in a table with two rows. I need to display 10 records per page like Google Search. I need only the Logic(Pagination) in Pure Java. No JSP and all..Thanks in Advance...

Cybernet,

2 8016

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Un-Answered Questions { Core Java }

What is the properties class in java programming?

1004

Explain about instanceof operator in java?

1056

What is the difference between array and array list in java?

1232

Define packages in java?

1002

Explain oops concepts in detail?

1029

Is it safe to install java on my computer?

1143

What is the difference between the prefix and postfix forms of the ++ operator?

1021

Tell us something about different types of casting?

943

Is static a singleton?

980

What is difference between array and vector?

1089

What is java in layman terms?

1012

Where can I find jdk in my computer?

966

Why we override equals() method?

1040

Why synchronization is important in java?

1046

When is the arraystoreexception thrown?

1025

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