How To Master Java 8 Interview Questions: A Guide

Java is one of the top programming languages in the world right now. There are a lot of job openings in this field and if you want to join this field. You should master the Java 8 interview questions to ace your Java 8 interviews and get placed in this field.

So in this blog post we will tell you about Java 8 interview questions, scenario based Java 8 interview questions , Java 8 coding questions for experienced and spring boot interview questions.

Java 8 Interview Questions for Freshers

What are the top features of Java 8?

  • Lambda expressions
  • Date API
  • Stream API
  • Functional interface

What do you mean by lambda expression?

The lambda expression was added to Java 8 to give users a way to call an anonymous function without using the function’s name. A lambda entity has a functional set of arguments.

What are the top advantages of using Java 8?

1. Makes the code highly readable
2. Increases the reusability of the code
3. makes code size compact
4. gives easier testing methods

What do you mean by functional interfaces in Java 8?

Functional interfaces in Java 8 means the interfaces having one single abstract method.

What is the difference between Predicate & Function?


Returns as true or false and used as an assignment target for lambda expressions.


It returns as an object and can be used for method references and lambda expressions.

What are the default methods in Java 8?

Interfaces in Java 8 that use the ‘default’ keyword are called “default methods.” Java 8 adds default methods so that users can use backward compatibility and get the same features they had before.

Can a user create a personal functional interface?

Yes, a user can create a personal functional interface.

What do you mean by method reference in Java 8?

With a Java 8 feature called “method reference,” you can point to a method without having to run it. It is a short way to describe a Lambda.

What is Nashorn in Java 8?

Nashorn is a new engine for handling JavaScript code that came with Java 8. It follows the ECMA JavaScript specs more closely and runs faster than Rhino, which it replaced.

JJS in Java 8?

JJS is the tool for the command line that comes with Java 8. It is used to run code written in JavaScript without any problems using only the console.


Java 8 Interview Questions for Experienced

When is the best time in Java 8 to use the Stream API?

The Stream API in Java 8 can be used well if a Java project needs to do any of the following:

  • Do things with a database
  • Don’t do things quickly.
  • Write programs in a functional way.
  • Perform multiple processing
  • Use pipeline operations
  • Use repetition on the inside.

How was the base64 decoder created in Java 8?

The Base64 class has a method called getDecoder() that returns a Base64.Decoder. Using the Base64 encoding method, this can be read.

How can you find and remove duplicate elements from a list using Java 8?

Stream operations and a collection, followed by the Collections.toSet() method, make it easy to list and remove duplicate parts. This should get rid of any items in the list that are already there more than once.

Give examples of terminal operations in Java 8?

  • Count
  • Min
  • Max
  • Reduce
  • toArray
  • anymatch
  • allMatch

Also Read:

Secrets of the Java Static Keyword: Tips and Tricks

Give some examples of intermediate operations in Java 8?

  • Distinct()
  • Limit(long n)
  • Filter(Predicate)
  • Map(Function)
  • skip(long n)

What are metaspace and PermGen in Java 8?

PermGen was used by the Java Virtual Machine to store classes until Java 7. Metaspace has now taken its place.

Metaspace has a huge edge over PermGen in that it can grow at any rate, while PermGen has a maximum size that can’t be changed.

What do you mean by stream pipelining?

Stream pipelining is the process of linking together different tasks. Pipelining does this by separating stream processes into two groups: those that happen in the middle and those that happen at the end. Each intermediate action gives back an instance of the stream when it runs. So, a user can set up a processing pipeline by setting up any number of intermediate actions to process data.

What do you mean by spliterator?

The word is a combination of “splittable” and “iterator,” and it is a new feature in Java SE 8. It is used by the Stream API to internally run over streams in parallel or in order.

Spring Boot Interview Questions

What do you mean by spring boot?

Spring Boot is a Spring plugin that gives the Spring framework the RAD (Rapid Application Development) feature.

It is used to make spring-based apps that can run on their own because they don’t need much spring setup.

What are some advantages of spring boot?

  • Make Spring apps that run on their own and can be started with java -jar.
  • You can easily embed Tomcat, Jetty, or Undertow. You don’t have to put WAR files into use.
  • It gives you “starter” POMs with opinions to make your Maven setup easier.
  • Whenever possible, it immediately sets up Spring.

Tell me some features of spring boot?

  • Helps in web development
  • Has spring application
  • Has admin features
  • Has application events and listeners

How to make simple spring boot applications?

To put together a request. We use the STS (Spring Tool Suite) IDE, which has a step-by-step explanation of the different steps.

Tell me some properties of spring boots?

Spring Boot has a number of settings that can be set in the file of our project. There are defaults for these features, which you can change in the properties file. Properties are used to set values such as the server port number, how to join to a database, etc.


We have discussed Java 8 interview questions, scenario based Java 8 interview questions , java 8 coding questions for experienced and spring boot interview questions. I hope this blog post will help you to prepare well for your upcoming Java 8 interviews. Rewise these questions before your Java 8 interview to ace it.

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