Interview

1. Introduction Abstraction is a concept of exposing only essential details and hiding implementation details. It is one of the essential OOPs concept apart from encapsulation, inheritance and polymorphism. Abstraction retains only information which is most relevant for the specific purpose. For example: ArrayList stores objects sequentially as list, and you can use the add() method […]

In this post, we will see most important Oops interview questions in java. 1. What are some core concepts of OOPS in java? Core concepts of OOPs are : Polymorphism Abstraction Encapsulation Inheritance 2. What is Abstraction? Abstraction is a concept of showing only important information and hiding its implementation.This is one of the most […]

Exceptional handling is one of the most important topics in core java. Here is list of questions that may be asked on Exceptional handling. Question 1: What is Exception ? Answer: Java doc says “ An exception is an event, which occurs during the execution of a program, that disrupts the normal flow of the program’s […]

In this tutorial, we are going to see Method overloading and overriding interview questions. 1. What is method overloading? Answer: If two or more methods have same name, but different argument then it is called method overloading. For example: Array’s sort method have many overloaded versions. You can sort array of double, int, String etc. 2. […]

In this tutorial, we are going to see Multithreading interview questions with answers. Here is list of Java Multithreading interview questions. Java multithreading interview questions 1. What is thread in java? Answer: Thread can be called as light weight process. It can be referred as smallest part of process which can be executed concurrently with […]

In this post, we are going to see difference between notify and notifyall in java. notify(): When you call notify method on the object, it wakes one of thread waiting for that object. So if multiple threads are waiting for an object, it will wake of one of them. Now you must be wondering which […]

In this tutorial, we are going to see differences between process and thread in java. If you are working on multithreading in java, it is good to know differences between process and thread. How multithreading can improve performance by executing code in parallel. Process vs Thread: The process can be referred as program in execution […]

In this tutorial, we are going to see difference between throw and throws in java. throw: throw keyword is used to throw any custom exception or predefine exception. For example: Let’s say you want to throw invalidAgeException when employee age is less than 18. Create a Employee class as below. [crayon-6833bcb46975a833103129/] Create InvalidAgeException class as […]

Serialization is one of most important concept in java. If you are going to face core java interview, then you might be asked some questions from Serialization. Java Serialization Tutorial: Serialization in java Java Serialization interview questions and answers serialversionuid in java serialization externalizable in java Transient keyword in java Difference between Serializable and Externalizable […]