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 3843

why interaction with server using javascript is difficult

1 3777

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 8766

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 6708

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

2029

What is difference between abstract class & final class

7 26789

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 5924

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

Accenture,

4 13743

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

Accenture,

6 10794

what is the Yield() method used in threads?

Accenture,

4 8419

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

Accenture,

8 10451

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

Accenture,

4 7381

What is Hash Code in Java?

Cognizant,

6 15754

What are uses of Hash Code?

Cognizant,

2 7357

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 7909

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Un-Answered Questions { Core Java }

What is the purpose of the system class in java programming?

1027

What is integer valueof?

1061

What are the restrictions imposed on method overriding?

970

What is JVM and is it platform independent?

999

Give the difference between the println method and sqrt method?

1043

What do you understand by soft reference?

992

What checkbox method allows you to tell if a checkbox is checked?

952

Which methods cannot be overridden in java?

934

Why hashset is used in java?

1018

What are the features of java?

1022

If a class is declared without any access modifiers, where may the class be accessed in java programming?

1147

What is the final variable?

1179

What is method with example?

1036

What is the range of a character variable?

947

What does indexof mean?

960

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