The way organizations hire JAVA Developers is intricate. Understanding the
organizational complexities involved in hiring and onboarding can help you chalk out a
plan for yourself. In order to reach the onboarding phase, you ought to go through a
rigorous hiring process which can be draining.
And the most difficult part? The Interview!
The interviews can make or break your game. There are preliminary rounds, but the
interview is the real check of the candidate’s ability as well as the first, and
probably the only interaction recruiters have with the candidate - before they
formally onboard them.
JAVA development is a lucrative career and with the increasing competitiveness, the
difficulties in the interview process are also surmounting. Thus, it’s essential to
be aware of what holds importance and what does not.
Let’s take a look at the most important JAVA Developer Interview Questions, that
every developer must have on their tips to ace the interview.
Top 10 JAVA Questions that can help you ace your interview
1. What is the difference between Overloading and Overriding?
When you have two methods with exactly similar names but different properties, then
we call it Overloading. On the other hand, Overriding refers to a condition when two
methods with identical names and properties exist, but the two are present in a
parent and child class respectively.
2. What do you mean by a Singleton Class?
A singleton class can only have one object at a time. In other words, a singleton
class can have only a single instance of a class.
It only permits one instance of itself to be constructed and provides access to that
instance. It has static variables that may be used to create unique and private
instances of itself. It's used when a user wishes to limit the number of objects
that may be instantiated by a class. This becomes essential when a single item is
necessary to coordinate operations throughout a system.
3. How are JVM, JRE, and JDK different?
JVM (Java Virtual Machine): The JVM (Java Virtual Machine) is a run-time
engine that allows Java programs to run. JVM is the module that executes the main
function in Java programming. JVM is a part of JRE.
JRE (Java Runtime Environment): A runtime environment in which Java bytecode
may be executed is referred to as a JRE. It creates the JVM (Java Virtual Machine)
and all of the class libraries and other support files that the JVM needs to
execute. As a result, JRE is a software package that includes everything needed to
run a Java program. In a nutshell, it's a physical implementation of the Java
JDK(Java Development Kit): It's the utility required for compiling,
documenting, and packaging Java projects. JDK comprises the Java Runtime Environment
(JRE), which offers resources for Java developers and is available for free. It
contains an interpreter/loader, a compiler (javac), an archiver (jar), a document
creator (JavaDoc), and other Java development tools in addition to JRE.
4. What is Constructor Chaining?
Constructor chaining is the sequence of executing constructors when an object is created
in Java. It's useful when we want to call a series of constructors one after the other
with just one instance. Constructor chaining happens as a result of inheritance. The
inheritance chain might contain any number of classes.
On creating an instance of the derived class, the constructors initially invoked
belong to the inherited or base class. Following this, the constructors of the
derived or calling class are invoked.
5. What is Object Cloning?
Object cloning, as the name suggests, refers to the process of creating a copy of the
existing object. In order to sustain object cloning, a class would need to implement the
java.lang.Cloneable interface and override clone() method from the Object class.
The syntax of the clone()method is :
protected Object clone() throws CloneNotSupportedException
The exception ‘CloneNotSupportedException' is thrown if the class of the object being
cloned, does not implement the Cloneable interface.
6. What are Collections in JAVA?
In Java, a collection is a framework that allows you to store and modify a set of
objects. All data actions, including searching, sorting, insertion, mutation, and
deletion, can be accomplished using Java Collections. An assemblage of different objects
to demonstrate a single unit is known as the Collection. The two major interfaces of
Java Collections are the Collection Interface (java.util.Collection)
and Map Interface
7. What do you mean by JAVA interfaces?
According to Oracle, an interface can be defined as a group of associated methods with
empty bodies. It is the blueprint of a class that possesses abstract methods. Interfaces
provide a mechanism to implement abstraction in JAVA meaning an interface can only have
abstract methods and no method body.
Java Interface also represents the IS-A relationship.
8. Define the underlying concepts of OOP (Object Oriented Programming)
Object-Oriented Programming is the foundation of today’s development world. The
programming paradigm is being followed everywhere today. JAVA, being an object-oriented
programming language, demands strong OOPs concepts for any developer. Here are the
underlying principles of OOPs:
Clear understanding and distinction between the OOPs principles are essential.
9. What is the Static keyword in JAVA?
In Java, the static keyword is used to control memory. For methods and attributes, the
static keyword is a non-access modifier. Methods and attributes of static type can be
invoked without constructing an object of the class. The static keyword in JAVA can be
applied to variables, methods, blocks, nested classes, etc.
The following programming constructs can be Static:
- Nested Class
10. On a Scale of 10 — Where would your JAVA skills stand?
The aim behind this question is not to judge your JAVA proficiency, but to check the level of self-awareness you possess. Ideally, you should always cite a grade that is less than the actual benchmark that defines your capability. The Reason? Since the difficulty of questions asked will always be on the higher end of difficulty.
Before you go to the interview…
Before you go to the interview make sure that you have the basics right. Dress smartly, carry yourself with confidence and be true to yourself. Don’t try to fake anything, the people on the other side are smart enough to catch your bluffs. A simple ‘No’ is better than the built-up stories. So make sure that you answer all the questions accurately and precisely.
And do you know that we are hiring rockstar JAVA developers? If you meet the requirements then apply with your best pitch at https://www.rulesiq.com/career.html