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

Core Java Interview Questions

Questions Answers Views Company eMail

In the HashMap, we know the values but we dont know the key, then how can we get the key from HashMap ?????

Kanbay,

4 9156

What is Transient and volatile

iFlex,

10 33804

What is the differenc between Enemuration interface and iterator interface according to accessing?

4 8489

what is the difference between static block and static method

Huawei,

19 57824

What is Marker interface in java? and what is clone?

Persistent, Wipro,

16 36625

what is the difference between equals method and ==

IBM, Professional Access, TCS,

17 27820

how many design pattern r there? and wht design pattern u use and why ?

HP,

5 11157

what is the difference b/w PUT and POST method to send data to the server

Mind Tree,

5 14353

In the first round, there are 30 aptitude and 30 java questions. We are suppose to finish both the papers within 60 minutes. I cleared this round. Next was test for programming skills. In this section, Some 7 n's were asked. 1. What is the difference b/w sleep(1000) and wait(1000) 2. what is the diff b/w static block and static function? 3. Write a program to validate IP address using string tokenizer. 4. Write a program to create singleton class 5. write a function to reverse the string 6. Write a prog to print prime nos upto n. EX: If n=9, It shld print 1,2,3,5,7 7. One program on collections- Write a program to print no. of times a number is repeating in an array. EX- {1,3,1,2,5,7,3,7,34,3,8,3} It should print: 1- 2 times 3- 4 times and so on 7. Write a func to print fibonocci series After this I had technical interview, which went on for. 60 mins or so. There were qn's about multi threading, Exception handling and collection classes. Knowledge about collections was very important for the post I was interviewed for.

Huawei,

1 12227

how can i connect to database in a applet ?

1 4938

when to use abstract class and when to use interface?

Exterro, iGate, IonIdea,

16 58711

what is difference between class and object?

College School Exams Tests, HCL,

43 91904

when,where and how to use abstract class and interface

2 5675

explain oops concepts with examples?

AbhiBus, Beeline, DELL, HCL, Satyam, TCS, VLS, Wipro,

29 204566

how can u create the object with out new operator

2 9071

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Un-Answered Questions { Core Java }

What is finalize()? Is finalize() similar to a destructor?

965

Is hashset sorted in java?

1185

How many bits are used to represent unicode, ascii, utf-16, and utf-8 characters?

1096

What are conditionals and its types?

1146

What is synchronization and why is it important in java programming?

940

What is dot operator?

1036

What is the difference between public, private, protected, and friend access?

1045

Can a static block throw exception?

1095

What is meant by class loader? How many types are there? When will we use them?

971

Can we define private and protected modifiers for the members in interfaces?

1103

Can we write class inside a class in java?

982

what do you mean by classloader in java?

1024

how to create multithreaded program? Explain different ways of using thread? When a thread is created and started, what is its initial state? : Java thread

1002

What are peerless components in java programming?

1013

How is java hashmap implemented?

1031

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