Core Java Interview Questions
Questions Answers Views Company eMail

Is it possible to write JAVA program without including any of the packages,such as "import java.io.*"; bcoz I instantly wrote a code without "import..." statement and runned the program on command Line & it worked. the code is: class Person { String name; int age; Person(String s,int a) { name = s; age = a; } accept() { System.out.println(name+"Hi!!!!!"); System.out.println(age); } } class Demo { public static void main(Strings args[])throws IOException { String name = args[0]; int age = Integer.parseInt(args[1]); Person p = new Person(name,age); p.accept(); } }

3 4227

1) There are 10 different threads in runnable state. Each having priority 1 to 10. How does the CPU schedules or executes these threads?

RBS,

2 5909

2) Suppose there are 5 directories having lot of files (say txt files) in each directory. 2 things :- 2.1) You want to search for filenames which have a particular pattern. 2.2) Out of these filtered files you want to search for a particular keyword or a search string. How can you achieve this?

RBS, TCS,

1816

3) Suppose you are a very rich person, having 50 rooms and you have lost the key for one of the room's. How effectively you can find this key? (Qs2 and Qs3 are related)

RBS,

3 7750

Suppose there is a System A which gives some output. This output is used as input by system B. The rate at which System A produces is faster than the rate at which system B consumes it. How can you improve this?

RBS,

1 5067

Suppose there is an Online shopping cart application having different objects like Cart, SelectionItem, Billing, COnfiguration, Authentication, Authorization, PersonalDetails etc. Out of this which one can be made a singleton pattern and why?

RBS,

2 9788

What is Co-Variant return type in method overriding?

RBS,

1 5076

7) Suppose there is Student class like class student { int age; string name; } We want to store these objects in a HashMap. Do we need to override any methods in Student class? If any which ones and why? what if i just override equals or just hashcode? what will be the results in both the cases?

CSC, Nagarro, RBS,

4 7541

Can an abstract class have a constructor?

RBS, Wipro,

1 8811

What is the life cycle of Servlet?

3 5177

JVM responsibility?

TCS,

6 14177

explain Anonynous inner class?

TCS,

6 7770

why is S capital in System.out.println ????

6 18409

what is difference between length and length()?

8 15692

how your day start in your company

1 3021


Post New Core Java Questions

Un-Answered Questions { Core Java }

Is 64bit faster than 32 bit?

564


What is the difference between processes and threads?

519


What is a buffer in computer?

500


What is the difference between double and float variables in java?

620


What are "class access modifiers" in Java?

592






Why is the main method declared static?

567


What is the difference between replace and replace all?

458


Why do we need hashset in java?

481


What is a file pointer?

504


Is it correct to say that due to garbage collection feature in java, a java program never goes out of memory?

560


which pattern is default in scanner package?

1785


How is the marker interface used in Java?

595


How do you find the maximum number from an array without comparing and sorting?

625


How do you use nextline in java?

493


Can a vector contain heterogenous objects?

578