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 4003

why interaction with server using javascript is difficult

1 3943

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 9157

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 6939

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

2104

What is difference between abstract class & final class

7 27284

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 6236

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

Accenture,

4 14034

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

Accenture,

6 11148

what is the Yield() method used in threads?

Accenture,

4 8749

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

Accenture,

8 10914

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

Accenture,

4 7671

What is Hash Code in Java?

Cognizant,

6 16211

What are uses of Hash Code?

Cognizant,

2 7591

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 8101

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Un-Answered Questions { Core Java }

What is the purpose class.forname method?

1018

What is the type of lambda expression?

1092

Explain enumeration in java?

1051

What is treeset in java?

1040

java Technical questions asked by JPMC

5146

How can you read an integer value from the keyword when the application is runtime in java? example?

1202

How does singleton class work?

1037

When arithmeticexception is thrown?

1081

How do you identify if jvm is 32-bit or 64-bit from java program?

1014

How can you share data between two thread in Java?

996

What is the purpose of the finally clause of a try-catch-finally statement in java programming?

1016

What is a line break example?

1049

How to use arraylist in java netbeans?

1098

Does variable declaration allocate memory?

1094

How do you check if an arraylist is not empty?

1195

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