Interview Questions.

Q1. What Is The Main Difference Between Java Platform And Other Platforms?

The Java platform differs from most other systems within the experience that it’s a software-based totally platform that runs on top of other hardware-based totally systems.

It has two additives:

Runtime Environment

API(Application Programming Interface)

Q2. What Is The Use Of The Finally Block? Is Finally Block In Java Guaranteed To Be Called? When Finally Block Is Not Called?

Finally is the block of code that executes usually. The code in eventually block will execute even though an exception is befell. Finally block is NOT called in following situations

If the JVM exits while the strive or catch code is being done, then the ultimately block won't execute. This may additionally occur because of System.Exit() name.

If the thread executing the strive or seize code is interrupted or killed, the in the end block might not execute even though the application as a whole maintains.

If a exception is thrown in sooner or later block and no longer handled then closing code in eventually block might not be completed.

Q3. What Is A Pointer And Does Java Support Pointers?

Pointer is a reference take care of to a memory region. Improper dealing with of guidelines ends in memory leaks and reliability troubles for this reason Java doesn’t assist using suggestions.

Q4. Difference Between Final, Finally And Finalize ?

Final is used to apply restrictions on magnificence, technique and variable. Final class can’t be inherited, very last approach can’t be overridden and very last variable price can’t be changed.

Finally is used to location vital code, it'll be finished whether exception is treated or no longer.

Finalize is used to perform clean up processing just before object is rubbish collected.

Q5. What Is The Difference Between Creating String As New() And Literal?

When we create string with new() Operator, it’s created in heap and now not introduced into string pool whilst String created the use of literal are created in String pool itself which exists in PermGen vicinity of heap.

String s = new String(“Test”);

does not  put the item in String pool , we want to call String.Intern() approach that is used to place  them into String pool explicitly. Its most effective while you create String object as String literal e.G. String s = “Test” Java routinely put that into String pool.

Q6. When Abstract Methods Are Used?

If you need a class to incorporate a particular method but you want the actual implementation of that method to be determined by way of infant instructions, you may claim the method in the parent class as summary.

Q7. What Are Wrapper Classes?

These are training that permit primitive types to be accessed as items.

Example: Integer, Character, Double, Boolean etc.

Q8. What Do You Mean By Platform Independence?

Platform independence me that we can write and assemble the java code in a single platform (eg Windows) and can execute the elegance in any other supported platform eg (Linux,Solaris,and so forth).

Q9. What Is The Difference Between An Interface And An Abstract Class ?

An abstract class will have example methods that implement a default behavior. An Interface can only declare constants and example strategies, but can not put into effect default conduct and all techniques are implicitly abstract. An interface has all public individuals and no implementation.