Top java puzzles

HashMap Interview Questions in Java

This article provides a collection of frequently asked Java HashMap Interview Questions interview questions and answers.   Java HashMap Interview Questions Can we synchronize a HashMap ?   Can we add duplicate keys in a HashMap ?   What happens to the value if we add a duplicate key with new value ? Is is […]

Java 8

Predicate vs Function in Java 8

Java 8 Predicate and Function   Both Predicate and Function are predefined functional interfaces introduced in JDK 8.   These are added in java.util.function package.     Predicate Interface   This is represented as Predicate<T> where T is an object type input. The purpose of Predicate<T> is to decide if the object of type T […]

Java 8

Top Java 8 Interview Questions and Answers

This post contains interview questions related to new features introduced in java 8 .   What is a lambda expression ? What are advantages of lambda expression ? What is a functional interface ? What is the type of a lambda expression ? What is the target type of a lambda expression ? What is the […]

Java Interview questions – Part 4

  Can a class be declared both abstract and final ? If not, why ?   We can not declare a class both abstract and final. This is because, the keyword abstract represents an incomplete class which depends on the subclasses for its implementation. Creating a subclass is compulsory for a abstract class . final […]

J2EE Interview Questions – Part 2

Click on below link to see part 1 of the J2EE interview questions:  J2EE Interview Questions   Here are the next set of J2EE interview questions & answers.   Difference between HTTPServlet and GenericServlet   GenericServlet is protocol independent. HttpServlet extends GenericServlet and provides support HTTP protocol specific methods like goGet() and doPost().   Difference between […]