Sample Interview Questions For Core Java
Dear Visitors herewith we are listing some sample expected questions asked during Interview Sessions. This Questions is only for your references. Refer the suitable books and prepare the answers for this questions for your satisfaction.
Why Java is not 100% pure object oriented language?
Explain working of Java Virtual Machine (JVM)
why java does not support Multiple Inheritance?
When we are sending the serialized array object thro the network, what is being passed ? is the value or the reference ?
JVM is platform independent/dependent?why? 2) which one is faster in execution Array List or Array? why?
When you have an object passed to a method and when the object is reassigned to a different one, then is the original reference lost
What is heap in Java
Can a method be static and synchronized
Will there be a performance penalty if you make a method synchronized? If so, can you make any design changes to improve the performance
What is MVC architecture
What are interfaces? or How to support multiple inheritance in Java?
Difference: Java Beans, Servlets
Why java does not support Multiple Inheritance?Why java is not pure Object Oriented?
What is the Difference between Design Pattern and Architecture?
How an Hashtable can change the iterator? Can a HashMap change the iterator?
What is phantom memory
In Java, how are objects / values passed around
What is EJB
How would you implement a thread pool
What design patterns have you used
How to use C++ code in Java Program?
Difference: AWT, Swing
How do i upload a file from client side to server side using servlet and jsp this will happen when I click upload button on web-page?
How can we take various inputs from user as int,char,string,float etc ?
What are the different kinds of exceptions? How do you catch a Runtime exception
Do primitive types have a class representation
What are the differences between C++ and Java
How does serialization work
What are the differences between ArrayList and a Vector
Disadvantages of Java
Explain the importance of "static"keyword
It is a saying that static methods in JAVA programs should be minimised. What is the reason for this? any problems arise or there is any performance measures to be looked into it.
Why multiple inheritance using classes is disadvantage in java
What are the differences between JIT and HotSpot
How all can you free memory
How can you do multiple inheritance in Java
How does garbage collection work
How would you declare a SingleThreaded servlet
What is the interface of thread?
What is BYTE Code?
Whether a Class,Method can be garbage collected or not?How?
Give example of : High severity & Low priority
Write a program that singleton objects returns two instances?
What is a memory footprint? How can you specify the lower and upper limits of the RAM used by the JVM? What happens when the JVM needs more memory
Does java do reference counting
What is data encapsulation? What does it buy you
What are the differences between AWT and Swing
How are memory leaks possible in Java
How can you swap two variables without using a third variable?
Whether private,protected method can be overloaded,overrided or not?
What do you meant by private constructor? why somebody declare only private constructor.
Does JVM maintain a cache by itself? Does the JVM allocate objects in heap? Is this the OS heap or the heap maintained by the JVM? Why
What does a static inner class mean? How is it different from any other static member
How would you pass a java integer by reference to another function
What are the differences between EJB and Java beans
How can u move/drag a component placed in Swing Container?
Does Java have "goto"?
Why ArrayList is faster than Vector?
Is java a fully object oriented programming or not? if not why?
Whether we can set the time implicitly for the garbage collection?
What are the disadvantages of reference counting in garbage collection
How do you declare constant values in java
What is reflection API? How are they implemented
How would you keep track of a session
What are STRUTS
What is the purpose of interface? And tell the difference between the class and interface?
What is the meaning of "final" keyword?
Meaning - Abstract classes, abstract methods
What is the basic difference between Java and .Net
Write program for single objects returns two instances?
Is it advisable to depend on finalize for all cleanups
How all can you instantiate final members
What is the primary advantage of XML driven Java Beans
Explain the keywords - native, transient, volatile, finally
Explain Servlet and JSP life cycle
Can I create final executable from Java?
Difference ? Java, C++
What is the difference between an object and an instance? And give me a real time example to differentiate these two?
When you use a struts framework, where would you place your business logic
How is serialization implemented in Java
What are the primitive types in Java
Differences between HashList and HashMap, Set and List
What would happen if you say this = null
Explain Garbage collection mechanism in Java
Explain Java security model
How hashtable is synchronized?why hashmap is not synchronized? Can we make hashmap synchronized?
Can we declare multiple main() methods in multiple classes.ie can we have each main method in its class in our program?
Is there a separate stack for each thread in Java
What is the sweep and paint algorithm
What do you like most with Ant
Sample Interview Questions For Core Java