Java Interview Questions Java Interview Questions Tips Top 55 Core Java Interview Questions

Top 55 Core Java Interview Questions :

What is the difference between an Interface and an Abstract class ?
What is the purpose of garbage collection in Java, and when is it used ?
Describe synchronization in respect to multithreading ?
What are pass by reference and passby value ?
Difference between HashMap and HashTable ?
Difference between Vector and ArrayList ?
What is static keyword in java ?
What do you mean by platform independence ?
What is the difference between a JDK and a JVM ?
What is Singleton class ?
What is finalize() method ?
What is an Exception ,Checked Exceptions,Runtime Exceptions ?
When throws keyword is used ?
How finally used under Exception Handling ?
What is Polymorphism ?
Define immutable object ?
What is Comparable Interface ?
Explain the Java Program : public static void main (String args[ ]) ?
What is static block ?
What is function overloading ?
What is function overriding ?
What is final class ?
What is NullPointerException ?
What invokes a thread's run() method ?
Does it matter in what order catch statements for FileNotFoundException and IOException are written ?
What is the difference between yielding and sleeping ?
What is the difference between the Reader/Writer class hierarchy and the InputStream/OutputStream class hierarchy ?
What is Serialization and deserialization ?
What's the difference between constructors and other methods ?
What's the difference between the methods sleep() and wait()?
What is a transient variable ?
What is synchronization ?
What will happen if static modifier is removed from the signature of the main method ?
What is the difference between error and an exception ?
Is it necessary that each try block must be followed by a catch block ?
What are synchronized methods and synchronized statements ?
Where and how can you use a private constructor ?
Describe life cycle of thread ?
Why Generics are used in Java ?
Why Strings are immutable ?
How to make a java class immutable ?
Deep copy and shallow copy ?
What is synchronization? Object level locking and class level locking ?
Can you assign null to this reference variable ?
How to override equals and hashCode() methods ?
What happens to the static fields of a class during serialization ?
How are Observer and Observable used ?
What is OutOfMemoryError in java ?
What is the use of the finally block ? Is finally block in Java guaranteed to be called ? When finally block is NOT called ?
What is Marker interface ? How is it used in Java ?
Can you make constructor final ?
Can we synchronize the constructor of a Java Class ?
How many types of memory areas are allocated by JVM ?
What is Java classloader ? Explain ?

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