Example & Tutorial understanding programming in easy ways.

What is garbage collection?

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What do you understand by Synchronization?

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What are different types of access modifiers?

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When we can declare a method as abstract method ?

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Java Virtual Machine (JVM)

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Can abstract modifier be applied to a variable?

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What is abstract class in java?

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Can we define abstract class (as outer class) and class ( inner class) in java ?If Yes give an example .

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How to define an Abstract class?

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Why we define constructor in abstract class in java when we can't initialized it abstract class. Or how constructor of abstract class can used. Give an example

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Can we define abstract class (as inner class) and class ( outer class) in java ?If Yes give an example?

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Abstract method

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Can we declare abstract method private ?

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Can abstract methods synchronized?

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What is interface?

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How to define an Interface?

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Can we create a interface within interface ?If Yes then give an example .How we can call inner interface?

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Can we declare a enum within interface ?If Yes then give an example .How we can call enum ?

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What is output of following ?explain why?

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How many number of non-public class definitions can a source file have?

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How many number of public class definitions can a source file have?

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What happened If we compile and run following code?

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What happens if parent is not serialized and child class are serialized?

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What is OOPS(Object Oriented Programming)?

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What is the difference between procedural and object-oriented programs?

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What is the difference between Assignment and Initialization?

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What is OOPS(Object-Oriented Programming) principle?

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What is encapsulation principle?

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Explain the Inheritance principle.

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Explain the Polymorphism principle.

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Explain the different forms of Polymorphism.

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What are Class, Constructor and Primitive data types?

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What is an Object and how do you allocate memory to it?

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What is the difference between constructor and method?

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What are methods and how are they defined?

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What is the use of bin and lib in JDK?

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What is casting?

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How many ways can an argument be passed to a subroutine and explain them?

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What is the difference between an argument and a parameter?

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What are Access Specifiers available in Java?

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Describe the wrapper classes in Java.

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What is the class variables ?

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Why there are no global variables in Java?

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What is the difference between class variable, member variable and automatic(local) variable

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When are static and non static variables of the class initialized?

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When are automatic variable initialized?

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What is method Overriding?

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What restrictions are placed on method overriding?

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What is Method overloading?

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What restrictions are placed on method overloading?

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What is the difference between Overloading and Overriding?

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Can overriding methods have different return types?

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Can constructors be overloaded?

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If you use super() or this() in a constructor where you us it in the constructor?

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What is difference between ArrayList and vector?

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What is difference between HashMap and HashTable?

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What is difference between Arrays and ArrayList ?

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What is difference between HashMap and HashTable?

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What is difference between Arrays and ArrayList ?

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Describe the feature of try-with-resorce feature of jdk 1.7?

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What is difference between List and Set?

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When to use ArrayList or LinkedList?

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What is difference between iterator access and index access?

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Which all classes implement Set interface?

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Where you use List and where ArrayList?

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If an ArrayList has to be iterate to read data only, what are the possible ways and which is the fastest?

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What are the classes implementing List interface?

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if accessing through iterator is slow then why do we need it and when to use it?

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Which design pattern Iterator follows?

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How to sort list in reverse order?

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Can a null element added to a Treeset or HashSet?

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How to sort list of strings - case insensitive?

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How to make a List (ArrayList,Vector,LinkedList) read only?

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How can Arraylist be synchronized?

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How we can sort any class on the behalf of the properties of collection. Like we has a collection of named Employee objects we need shortlist by using Employee ID.

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What is ConcurrentHashMap?

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Which is faster to iterate LinkedHashSet or LinkedList?

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Which data structure HashSet implements?

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Arrange in the order of speed - HashMap,HashTable, Collections.synchronizedMap,concurrentHashmap?

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What is the use of Dimond operator feature of java7?

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What is IdentityHashMap?

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What is WeakHashMap?

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What is an exception?

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Which is superclass of Exception?

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What is Exception and Error ?

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What is exception handling?

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What is a Thread ?

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Collection framework in java interview questions

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What is the difference between thread and process?

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1. What is OOPS?

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1. What is OOPS?

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2. Write basic concepts of OOPS?

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How do you implement Thread in Java?

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When to use Runable and Thread in java?

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What is the difference between start() and run() method of thread class

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Difference between Runnable and Callable in Java?

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3. What is Encapsulation?

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4. What is Polymorphism?

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5. What is Inheritance?

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6. What is multiple inheritance and does java support?

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7. What is an abstraction?

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What is thread-safety?

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Whar is race condition in multi-threading in java?

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8.What is the difference between abstraction and encapsulation?

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What is Executors Framework ?

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How to stop thread in Java?

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9. what is the use of super keyword

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What happens when an Exception occurs in a thread?

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10.what is the Advantage of OOPs over Procedure-oriented programming language

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Why wait, notify and notifyAll are not inside thread class?

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What is ThreadLocal variable in Java?

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11.What is final variable and Use of final variable

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You have thread T1, T2 and T3, how will you ensure that thread T2 run after T1 and thread T3 run after T2?

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What does yield() method of Thread class do?

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Difference between submit() and execute() method thread pool in Java?

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What are the different states of a thread\'s lifecycle?

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What is use of synchronized keyword?

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12.What is final class - Using final to prevent inheritance?.

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13.what is final Method.

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14.what is the use of final keyword with Variables?

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You have thread T1, T2 and T3, how will you ensure that thread T2 run after T1 and thread T3 run after T2?

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15.point to be remember keyword final.

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What is Serialization? given an example.

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17.Can you create a program without main method ?.

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what is use of serialization in java?

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why serialization in java?

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how to serialization in java?

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what is the 6 usage of this keyword in java?.

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16.what is Runtime polymorphism or Dynamic Method Dispatch

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What is a Serial Version UID (serialVersionUID) and why should I use it?

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why serialversionuid is required?

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How many methods in the Serializable interface?

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what is the difference between serializable and externalizable interface in java?

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What is the difference between static and dynamic binding ?

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Can we override the static method?

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What are the advantages or usage of threads?

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What is operator overloading?

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Why Multiple Inheritance is Not Supported in Java?

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How downcasting is possible in java?

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What is function overloading?

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When to use private constructors in Java?

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what is transient variables in java with example?

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What is Serialization and deserialization in java given with example?

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what are the different approach to make object Serializable? Other than Serialization.

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What happens if the object to be serialized includes the references to other serializable objects?

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What is the Difference between volatile and transient keyword in Java?

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Serialization is NOT save the value of static class attributes. Why static variables are not serialized?

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Can we overload main() method?

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what are the the main keyword used in exceptation handling?

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what are the the main keyword used in exceptation handling?

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Why we need Aggregation?

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Explain Java Exception Hierarchy followed by Throwable class?

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What are important methods of Java Exception Class?

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What is the relationship between a class and an object?

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What is difference between Checked and Unchecked Exception in Java?

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What is difference between throw and throws keyword in Java?

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What are access modifiers?

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How to write custom exception in Java?

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What is OutOfMemoryError in Java?

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What are different scenarios causing “Exception in thread main”?

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What are access modifiers?

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What is difference between final, finally and finalize in Java?

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What are the various types of constructors?

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What happens when exception is thrown by main method?

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What is the difference between constructor and method?

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Can we customize the Serialization process?

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What changes are compatible and incompatible to the mechanism of java Serialization?

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Can we have an empty catch block?

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What is the difference between Error and Exception?

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Can static block throw exception?

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What is finally block?

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Can we have a try block without catch or finally block?

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Can we have a try block without catch or finally block?

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what is the Difference between method Overloading and Overriding?.

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Can we have multiple catch blocks following a single try block?

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Is it possible to have finally block without catch block?

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Can you declare the main method as final?.

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When a finally block does not get executed?

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Can we handle more than one exception in a single catch block?

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How are the exceptions handled in java?

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What is difference between abstract class and interface?

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What is difference between ClassNotFoundException and NoClassDefFoundError?

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What is throw keyword?

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What is use of throws keyword?

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What are the possible combination to write try, catch finally block?

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What are the possible combination to write try, catch finally block?

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How to create custom Exception?

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What is JVM (Java Virtual Machine)?

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What is JIT (Just- in-Time) Compilation?

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What is Object Oriented Programming?

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What is StackOverflowError?

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what is Java Naming conventions?.

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What’s the difference between “Abstract” classes and “Interfaces”?

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What’s difference between Static and Non-Static fields of a class?

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What are Class loaders?

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What is Bootstrap, Extension and System Class loader?

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What is Reflection API in Java?

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What are the advantages of using exception handling?

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What’s the difference between static and dynamic class loading?

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What is String in Java? String is a data type?

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Why String is an immutable Object?

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What is use of synchronized keyword?

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What are different ways to create String Object in java?

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Can we use String in switch case?

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what is the Difference Between String , StringBuilder and StringBuffer Classes in java?.

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Can a thread call multiple synchronized methods on the object of which it hold the lock?

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Can static methods be synchronized?

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How many types of memory areas are allocated by JVM?

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What are the various access specifiers for Java classes?

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What is the difference between static binding and dynamic binding in java?

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Can two threads call two different static synchronized methods of the same class?

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What are synchronized methods and synchronized statements?

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When you will synchronize a piece of your code?

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Why synchronization is important?

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What is Java String Pool?

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Why String is popular HashMap key in Java?

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What is Reflection in Java and where is used?

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What are the disadvantage of using the reflection API?

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How can you get the class object from a class name?

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What are the basic Functionality of Reflection Api in Java?

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How to access private field using Reflection in Java?

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How to access private metod using Reflection in Java?

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what string method in java?

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what methods supported by String class in java?

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What is Dynamic Class Loading using java Reflection Api ?

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What do you understand by Executor Framework in Java, what is java executor framework

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How to terminate a thread in Executor Framework in java?

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Write a function to determine whether or not a string is a palindrome?.

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What is the role of Executors.unconfigurableExecutorService in Executor Framework?

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What are Difference Between String , StringBuilder and StringBuffer Classes with Example in Java ?

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What is a wrapper class in java? Explain with examples.

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What is the role of ExecutorService in Java?

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What is String subSequence methodin java?.

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What is difference between shutdownNow() and shutdown() in Executor Framework in java?

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Write a method that will remove given character from the String in java?

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How do you check if two Strings are equal in Java?

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How to Split String in java?

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What is Executors in java Executor Framework?

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What is the role of FutureTask and Future in java?

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What is the role of Executors.privilegedThreadFactory() in Executor Framework?

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What are differences between JVM,JRE and JDK ?

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Why Java does not support operator overloading ?

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How can we make String upper case or lower case in java?.

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What is the difference between creating string as new and literal in java?

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Can we define two methods in a class with the same name?

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What ie Thread Safety in java ?

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What are the different policy in Executor Framework?

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What is Anonymous Class in Java ?

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How to get return value of a callable thread in java Executor Framework?

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Why String is immutable or final in Java with example?.

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What is difference between String and new String() in java?

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What are the new features introduced in jdk 1.7?

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Can we compare String using == operator? What is risk?

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What is difference between Compare to and equals method in java?.

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What is binary literals feature in jdk 1.7?

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What is collection framework in Java? give its advantage?

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How to create String buffer in java?.

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What are the basic interfaces of Java Collections Framework?

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What is the benefit of Generics in Collections Framework?

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What are the Methods of Collection interface in Java?

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What stringbuffer method in java used?.

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What are difference between Iterator and ListIterator?

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What StringBuilder method in java used?.

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How we can use underscore in numeric lithrals in java 7?

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What is the String inside switch feature of java 7?

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How to use StringBulider method in java give example,and how to create it?.

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what is the multi-catch feature of java 7?

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What is the difference between Iterator and Enumeration ?

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What is an Iterator ?

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How do you traverse through a collection using its Iterator?

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How to obtain Array from an ArrayList ?

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What is the difference between Comparable and Comparator Interface?

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What is difference between HashMap and HashSet?

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What is difference between fail-fast and fail-safe?

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How to make a collection read only?

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what is the NIO.2 feature of java 7 new IO API?

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What is Garbage Collection in Java?

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what is the purpose of finalize() method in java?

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Why we override equals() method in java?

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What is legacy class in java ?

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Why we use Map interface? What are main classes implementing Map interface?

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Simple Example of ArrayList in Java .

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Simple Example of LinkedList in Java .

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Simple Example of ListIterator Interface in Java .

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Simple Example of HashSet class in Java .

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Simple Example of TreeSet class in Java .

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Simple Example of Sorting the elements in Java .

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Simple Example of PriorityQueue in Java .

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Simple Example of HashMap class in Java .

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Simple Example of LinkedHashMap class in Java .

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Simple Example of TreeMap class in Java .

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Which HTTP method is non-idempotent?

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Which HTTP method is non-idempotent?

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What is I/O in java?.

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How do I write text to a file?

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how to set file permissions in java?.

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What is FileInputStream and FileOutputStream in java explain?.

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How many ways can we read data from the keyboard?.

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How to delete temporary file in java?

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How to create temporary file in java?.

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How to get list of all files from a folder in java?.

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How to Filter the files by file extensions and show the file names in java?.

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How to Filter the files by file extensions and show the file names in java?.

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How to Filter the files by file extensions and show the file names in java?.

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How to compress and uncompress the data of a file in java?.

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How to create and store property file dynamically in java?.

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How to store and read objects from a file in java?.

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what is the diffrence b/w io and nio in java?.

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How to read file content using byte array in java?.

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How to get file URI reference in java?.

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How to get file URI reference in java?.

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How to get file last modified time in java?.

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How to Write file handling program to copy characters from one file to another in java?.

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How to count number of characters in a file in java

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