CORE JAVA

IS JAVA COMPLETE OBJECT ORIENTED?
What is the use of package in java?
How to write Java documentation?
What are the new features came in java1.5 ?
JVM arguments:
What is the difference between import package.* and import package.class in Java?
What is the difference between if(false) and while(false)?
What is java += assignment operator?
WHAT IS FINAL KEYWORD?
Where can final variables be initialized?
WHAT ARE THE KEY ACCESS MODIFIERS OR SPECIFIERS CAN BE USED BEFORE VARIABLES AND METHODS ?
WHAT ARE THE RANGES OF PRIMITIVES?
What is a compile constant expression?
WHAT IS ABSTRACT KEYWORD?
WHAT IS INTERFACE?
ACCESS MODIFIERS:
WHAT IS SYNCHRONIZED METHOD?
WHAT IS STRICTFP METHODS?
WHAT IS THE DIFFERENCE BETWEEN ARGUMENTS AND PARAMETERS?
WHAT IS CONSTRUCTOR?
WHAT IS CONSTRUCTOR CHAINING?
HOE THIS() AND SUPER() CAN BE USED IN CONSTRUCTOR?
PRIMITIVES AND REFERENCE VARIABLE?
DEFAULT VALUE OF PRIMITIVES AND OBJECT REFERENCE?
WHAT IS ARRAY?
WHAT IS TRANSIENT VARIABLE?
WHAT IS GARBAGE COLLECTION IN JAVA?
WHAT IS finalize() METHOD?
What is deamon thread?
WHAT IS LEGAL IDENTIFIER?
KEYWORDS IN JAVA:
WHAT IS DYNAMIC INITIALIZATION?
WHAT IS INSTANCE VARIABLE HIDING?
BYTE CODE MAGIC IN JAVA:
WHAT IS STATIC KEYWORD?
WHY main() IS STATIC?
WHERE static CAN NOT BE USED?
WHAT IS ENUMERATIONS?
FILE NAME AND CLASS NAME RELATION:
IS IT NECESSARY ALWAYS TO GIVE THE SAME FILE NAME AS CLASS NAME?
JAVA COMMENTS:
WHAT IS HAS-A AND IS-A RELATION?
WHAT IS METHOD OVERRIDING?
WHAT ARE THE METHOD OVERRIDING RULES?
WHAT IS METHOD OVERLOADING?
RULES OF METHOD OVERLOADING:
WHAT IS THE DIFFERENCE BETWEEN METHOD OVERLOAD AND METHOD OVERRIDE?
HELLO WORLD PROGRAM EXPLANATION:
WHY main() IS PUBLIC?
WHAT IS instanceof KEYWORD?
REFERENCE VARIABLE CASTING(UPCAST AND DOWNCAST)?
LEGAL RETURN TYPE:
SOME FACTS ABOUT EXTENDS AND IMPLEMENTS:
STACK AND HEAP AREA IN JAVA PROGRAM:
LITERAL VALUES FOR ALL PRIMITIVES:
PRIMITIVE TYPE CAST(IMPLECIT AND EXPLICIT)
SCOPE OF VARIABLES:
WHAT ARE DIFFERENT TYPES OF BLOCKS IN JAVA?
WHAT ARE STATIC BLOCKS AND INSTANCE BLOCKS?
WHAT IS WRAPPER CLASS?
WHAT IS valueof() METHOD?
WHAT IS xxxValue() METHOD?
WHAT IS parseXxx() METHOD?
What is the difference between Integer.parseInt and Integer.valueOf() ?
WHAT THE DIFFERENCE BETWEEN parseXxx() and valueOf() METHODS?
WHAT IS toString() and toXxxString() METHODS?
WHAT IS STRING CONCATINATION OPERATOR?
EXCEPTION HANDLING IN JAVA:
WHY WE WRITE THE CLEAN UP CODE IN finally BLOCK ?
What are cases that finally block wont be executed?
What can you catch when try block does not throw exception?
WHAT IS THE DIFFERENCE B/W static BLOCK AND CONSTRUCTOR?
STRING CLASS(IMMUTABLE):
What is String intern() method ?
Concat() IN String:
HOW String CLASS IS IMMUTABLE?
String CONCATINATION EXAMPLE:
HOW JAVA HANDLES STRING OBJECTS IN MEMORY?
WHAT IS THE DIFFERENCE BETWEEN String s="bhabani" and String s=new String("bhabani")?
IMPORTANT METHODS OF String CLASS:
WHAT IS THE DIFFERENCE BETWEEN length() and length?
StringBuffer VS StringBuilder:
WHEN SHOULD WE USE StringBuffer AND StringBuilder?
String VS StringBuffer OR StringBuilder:
IMPORTANT METHODS OF StringBuffer AND StringBuilder CLASS?
CHAINED METHODS IN STRING:
BEHAVIER OF == AND equals() IN STRING:
WHAT IS STREAM AND TYPES OF IO STREAM:
CREATING,DELETING AND RENAMIING FILES USING CLASS 'File':
HOW TO CREATE DIRECTORY THROUGH JAVA PROGRAM?
HOW TO LIST ALL THE CONTENTS INSIDE A DIRECTORY?
READING FROM CONSOLE:
HOW TO READ A TEXT FILE?
HOW TO WRITE A TEXT FILE?
WHAT IS SERIALIZATION?
What is serialVersionUID?
How to override toString():
How to override the equals() method?
What is hashCode()?
What is Collection Framework?
Collection hierarchy:
How Collection classes and interfaces related to each other?
What is collection,Collection and Collections?
Describe core collection interfaces:
Collection classes:
Collection interfaces:
Why Collection is made generic?
What is for-each style loop?
What is Iterator ?
What is List interface?
What is Set interface?
What is Map interface?
What is Queue interface?
Comparision between different Collection classes:
What is ArrayList ?
What is RandomAccess Interface?
The toString() method of collection:
How to put user defined Object in Collection ?
What is the difference between List and Set ?
How to obtain array from ArrayList?
What is HashSet class?
How HashSet checks for duplicates?
Why hashcode is not sufficient to insert the elements in HashSet and HasMap?
Why Searching is faster in HashSet than ArrayList?
How LinkedHashSet is different from HashSet?
What is TreeSet?
What is Comparator?
How to reverse a TreeSet?
How to create custom comparator?
What if you want to store user defined objects in TreeSet?
Using headset() and tailSet():
How to sort the elements of a list?
How to sort the elements of a list in reverse order?
What is ProrityQueue ?
What is the diff between Iterator and ListIterator ?
How to store the elements of Map in a Set ?
What is Map.Entry interface?
How to get the Collection view of keys and values of Map?
How to loop through a Map?
What are the Legacy classes?
What is Enumeration interface?
What is Vector ?
What is the difference between Vector and ArrayList?
What is load() and store() method of Properties?
Searching in Collection:
What is the difference between add() and set() in List ?
Difference between HashTable and HashMap ?
What is the difference between hashset and treeset?
What is the difference between HashTable and Properties ?
What are limitations of object arrays?
What are differences between arrays and collections?
What is RandomAccess Interface?
What is LinkedList class?
What is difference between ArrayList and Linked List?
what is difference Enumeration and Iterator?
Inserting null values in TreeSet and HashSet:
What is Comparable and Comparator interface?
What is IdentityHashMap?
What is WeakHashMap?
What is EnumMap ?
What is IdentityHashMap and WeakHashMap?
What is backed collection?
How to make the collection classes thread-safe?
What is generics?
Example of Generic class with one type parameter:
Example of Generic class having two type parameters:
How generics improves type safety?
What is the problem to create a generalized class of type object?
Can we pass primitives as type parameter in generics?
What is bound type generic class?
How to create generic method?
How to create generic constructor?
How to create generic interfaces?
Overriding methods in generic class:
Can we instanciate the type parameters?
What is erasure?
Ambiguity error in generics:
What is inner class?
How many class files are created in case of inner class?
What is static inner class?
what is Non-static inner class?
How this keyword works in inner class?
What is Local inner class?
Why local inner class object cannot use the local variables of the method the inner class is in?
What is Anonymous inner class?
What is multi threading?
What is the difference between multithreading and multiprocessing ?
What is main thread ?
How to create Thread?
Instantiating a Thread:
Can you override the run() method?
How to start a thread?
What if we call run() directly?
How to get and set the thread name?
How to run multiple threads?
Can we call run() method twice?
What are the Thread States?
What is Thread sleep?
What is Thread priority?
What is yield() method?
What is join() method?
What is the difference between sleep() and wait()?
What are the cases that Thread might leave the running state?
What is synchronization?
What is monitor?
What is Synchronized method?
Can static methods be synchronized?
What Happens If a Thread Can't Get the Lock?
What is deadlock?
How Threads communicate with each other?
What is wait(),notify(),notifyAll()?
Why the above three methods in Object class instead of Thread class?
What is DateFormat and SimpleDateFormat?
Is SimpleDateFormat is a Threadsafe class ?
Writing own annotation.
What is the benifit of clone() method ?
What is reflection.
What is Class.forName()?
What is the difference between java.sql.Date and java.util.Date?
What is loadfactor of hashtable?
How to customize java serialization?
Externalizable vs Serializable?