Java 8 interview questions

Java 8 Interview Questions(+ Answers)

Source: (baeldung.com)

A set of popular Java8-related interview questions and of course answers.

Outline:

  • A set of practical Collections-related Java interview questions
  • Q2. What Is a Functional Interface? What Are the Rules of Defining a Functional Interface?
  • Q2. Will the Following Code Compile?
  • 7. Lambda Expressions
  • Q2. Explain the Syntax and Characteristics of a Lambda Expression
  • 8. Nashorn Javascript
  • Q2. What Is JJS?
  • Q2. What Is the Difference Between Intermediate and Terminal Operations?
  • Q3. What Is the Difference Between Map and flatMap Stream Operation?
  • Q4. What Is Stream Pipelining in Java 8?
  • 10. Java 8 Date and Time API
  • 11. Conclusion

Top 30 Java 8 interview questions and answers – Java2Blog

Source: (java2blog.com)

There are lots of new features which were added in Java 8. Here is the list of important features:

Outline:

  • Top 30 Java 8 interview questions and answers
  • 3) What is lambda expression?
  • 5) What are functional interfaces?
  • 7) Can you create your own functional interface?
  • 8) What is method reference in java 8?
  • 9) What is Optional? Why and how can you use it?
  • 10) What are defaults methods?
  • 13) Can you provide some APIs of Java 8 Date and TIme?
  • 15) Do we have PermGen in Java 8? Are you aware of MetaSpace?
  • 25) Difference between Stream’s findFirst() and findAny()?
  • Java Date to LocalDate
  • Java LocalDate to Date
  • Java Stream to List
  • Convert LocalDateTime to Timestamp in Java
  • A In-Depth guide to Java 8 Stream API
  • Java Stream List to Map

Top 40 Java 8 Interview Questions & Answers [Most Important]

Source: (softwaretestinghelp.com)

In this Tutorial, we have provided the Most Important Java 8 Interview Questions & their Answers with Code Examples & Explanation.

Outline:

  • Top 40 Java 8 Interview Questions & Answers [Most Important]
  • Conclusion

Top 30 Java 8 interview questions and answers – Java2Blog

Source: (medium.com)

There are lots of new features which were added in Java 8. Here is the list of important features:

Outline:

  • Top 30 Java 8 interview questions and answers
  • 3) What is lambda expression?
  • 5) What are functional interfaces?
  • 7) Can you create your own functional interface?
  • 8) What is method reference in java 8?
  • 9) What is Optional? Why and how can you use it?
  • 10) What are defaults methods?
  • 13) Can you provide some APIs of Java 8 Date and TIme?
  • 15) Do we have PermGen in Java 8? Are you aware of MetaSpace?
  • 25) Difference between Stream’s findFirst() and findAny()?
  • Java Date to LocalDate
  • Java LocalDate to Date
  • Java Stream to List
  • Convert LocalDateTime to Timestamp in Java
  • A In-Depth guide to Java 8 Stream API
  • Java Stream List to Map

Top 50 Java 8 Interview Questions & Answers 2021 – Intellipaat

Source: (intellipaat.com)

Here is the list of the top 50 frequently asked Java 8 Interview Questions and answers in 2021 for freshers and experienced. Tips and Tricks for cracking Java 8 interview.

Outline:

  • Top Java 8 Interview Questions
  • 1. What are some of the important features that are introduced in Java 8?
  • 2. What is a lambda expression?
  • 5. What is the use of the @FunctionalInterface annotation?
  • 7. What is the use of the String::ValueOf expression in Java 8?
  • 9. What is the meaning of method reference in Java 8?
  • 11. What are default methods in Java 8?
  • 14. What were the issues that were fixed with the new Date and Time API of Java 8?
  • 15. What are PermGen and Metaspace in Java 8?
  • 17. Can the following piece of code compile successfully?
  • 18. What is Nashorn in Java 8?
  • 20. What is stream pipelining used for?
  • Intermediate Interview Questions
  • 24. Can you briefly explain the working of the random keyword in Java 8?
  • 25. What are collectors in Java 8?
  • 26. What is the easiest way to print the sum of all of the numbers present in a list using Java 8?
  • 27. Can JavaScript code be executed from Java 8 codebase?
  • 28. When is an ideal situation to use the Stream API in Java 8?
  • 30. Which class implements the encoder used for encoding byte data in Java 8?
  • 31. How is a Base64 decoder created in Java 8?
  • 33. What is a supplier in Java 8?
  • 34. What is a consumer in Java 8?
  • 37. What is the meaning of a Spliterator in Java 8?
  • 39. Can you name the common types of functional interfaces in the standard library?
  • 40. What are the similarities between map and flatMap stream operations in Java 8?
  • 43. What is the easiest way to find and remove duplicate elements from a list using Java 8?
  • 44. What is the use of the peek() method in Java 8?
  • 46. What is the easiest way to convert an array into a stream in Java 8?
  • 47. Why do you think you are the right fit for this Java Developer role?
  • 48. Do you have any past work experience in a production environment involving Java?
  • 49. Do you have any experience working in the same industry as ours?
  • 50. Do you have any certification to boost your candidature for this Java Developer role?

Top Java 8 Interview Questions and Answers in 2021 [Updated]

Source: (hackr.io)

For those who are not aware or miss the opportunity to learn about the latest additions can go through the following top 50 Java 8 interview questions and answers in 2021.

Outline:

  • Table of Contents
  • Top Java 8 Interview Questions and Answers
  • Davinder Pal Singh

learning-zone/java-interview-questions

Source: (github.com)

1000+ Java Interview Questions . Contribute to learning-zone/java-interview-questions development by creating an account on GitHub.

Outline:

  • Q. What are the types of Exceptions? Explain the hierarchy of Java Exception classes?
  • Types of Java Exceptions
  • Q. What is the difference between aggregation and composition?
  • Example: Since Organization has Person as employees, the relationship between them is Aggregation. Here is how they look like in terms of Java classes
  • Q. What is difference between Heap and Stack Memory in java?
  • Java Stack Memory
  • Difference
  • Q. What is JVM and is it platform independent?
  • Q. What is JIT compiler in Java?
  • Q. What is Classloader in Java? What are different types of classloaders?
  • Types of ClassLoader
  • Q. Java Compiler is stored in JDK, JRE or JVM?
  • Q. What is the difference between factory and abstract factory pattern?
  • 1. equals() and 2. hashcode() Class inherits methods from the following classes in terms of HashMap java.util.AbstractMap java.util.Object java.util.Map
  • Q. Can we import same package/class two times? Will the JVM load the package twice at runtime?
  • Q. Distinguish between static loading and dynamic class loading?
  • Q. What is the difference between transient and volatile variable in Java?
  • Q. How many types of memory areas are allocated by JVM?
  • Q. What will be the initial value of an object reference which is defined as an instance variable?
  • Q. How can constructor chaining be done using this keyword?
  • Q. Can you declare the main method as final?
  • Q. What is the difference between the final method and abstract method?
  • Q. What is the difference between compile-time polymorphism and runtime polymorphism?
  • Q. Can you achieve Runtime Polymorphism by data members?
  • Virtual function with Interface
  • Q. Can there be an abstract method without an abstract class?
  • Q. Can we use private or protected member variables in an interface?
  • Q. When can an object reference be cast to a Java interface reference?
  • Q. Give the hierarchy of InputStream and OutputStream classes?
  • Q. What is the purpose of the Runtime class and System class?
  • Q. What are assertions in Java?
  • Q. Can we have multiple public classes in a java source file?
  • Q. What is the difference between abstract class and interface?
  • Q. What are Wrapper classes?
  • Sl.No Primitive Type Wrapper class 01. boolean Boolean 02. char Character 03. byte Byte 04. short Short 05. int Integer 06. long Long 07. float Float 08. double Double
  • Q. What is Java Reflection API?
  • There are 3 ways to get the instance of Class class. They are as follows: forName() method of Class class getClass() method of Object class the .class syntax
  • 3. The .class syntax
  • Q. What is the default value of the local variables?
  • Q. How many types of constructors are used in Java?
  • Example: Parameterized Constructor
  • Q. What is the final variable, final class, and final blank variable?
  • Q. Name some classes present in java.util.regex package?
  • java.util.regex package MatchResult interface Matcher class Pattern class PatternSyntaxException class
  • Q. What is the purpose of using BufferedInputStream and BufferedOutputStream classes?
  • Q. How to set the Permissions to a file in Java?
  • Q. In Java, How many ways you can take input from the console?
  • Q. How can you avoid serialization in child class if the base class is implementing the Serializable interface?
  • Q. What is the purpose of using javap?
  • Q. What are autoboxing and unboxing? When does it occur?
  • Example: Autoboxing
  • Q. What is a native method?
  • Main.java
  • Compile and run javac Main.java javah -jni Main gcc -shared -fpic -o libMain.so -I${JAVA_HOME}/include \ -I${JAVA_HOME}/include/linux Main.c java -Djava.library.path=. Main
  • Q. The difference between Inheritance and Composition?
  • Example: Inheritance
  • Q. What is the difference between creating String as new() and literal?
  • Q. How can we create an immutable class in Java?
  • Example: StringBuffer
  • Example: StringBuilder
  • Some tools that do memory management to identifies useless objects or memeory leaks like: HP OpenView HP JMETER JProbe IBM Tivoli
  • Output Exception in thread “main” java.lang.OutOfMemoryError: Java heap space exceed
  • Q. Why String is popular HashMap key in Java?
  • Q. What is difference between Error and Exception?
  • Q. Explain about Exception Propagation?
  • Q. What are different scenarios causing “Exception in thread main”?
  • Throw Example
  • Throws Example
  • Q. The difference between Serial and Parallel Garbage Collector?
  • Q. What is difference between WeakReference and SoftReference in Java?
  • Q. What is a compile time constant in Java? What is the risk of using it?
  • Compile time constant must be: declared final primitive or String initialized within declaration initialized with constant expression
  • Q. How bootstrap class loader works in java?
  • Q. Why string is immutable in java?
  • Q. What is Java String Pool?
  • Q. How Garbage collector algorithm works?
  • Q. How to create marker interface?
  • Q. How serialization works in java?
  • Q. Java Program to Implement Singly Linked List?
  • Q. While overriding a method can you throw another exception or broader exception?
  • After adding IOException
  • Q. What is difference between ClassNotFoundException and NoClassDefFoundError?
  • Q. What do we mean by weak reference?
  • Example: Static Polymorphism
  • Example: Runtime polymorphism
  • Q. What are the different types of JDBC Driver?
  • Q. How Encapsulation concept implemented in JAVA?
  • Q. Do you know Generics? How did you used in your coding?

Top 25 Java 8 Interview Questions and Answers in 2021 [Updated]

Source: (simplilearn.com)

Here are the top 25 Java 8 interview questions that will help you to prepare and crack an interview. So, read on and get prepared.

Outline:

  • Top 25 Java 8 Interview Questions and Answers in 2021
  • What is Java 8?
  • 4. What is a Lambda Expression, and why use them?
  • 8. What does the term “method reference” mean in the context of Java 8?
  • 9. What is optional, and what is it best used for?
  • 10. What is Type Inference?
  • 12. Why are default methods needed in the interface?
  • 13. What is Java 8 StringJoiner class used for?
  • 15. What is a stream, and how does it differ from a collection?
  • 16. What is a default method, and when does it get used?
  • 18. What is Nashorn, and what advantages does it provide?
  • 19. What is stream pipelining?
  • 23. What is a Spliterator?
  • 24. Explain the difference between predicate and function.
  • 25. What’s the difference between findFirst() and findAny()?
  • Do You Want a Career in Java?
  • Recommended Resources

Java SE 8 Interview Questions and Answers (Part-1) – JournalDev

Source: (journaldev.com)

Java 8 interview questions and answers, java 8 features interview questions, java 1.8 interview questions and answers, Java SE interview questions.

Outline:

  • Java SE 8 Interview Questions and Answers (Part-1)
  • Java 8 Interview Questions and Answers
  • Why do we need change to Java again?
  • What is Lambda Expression?
  • What is a Functional Interface? What is SAM Interface?
  • Is is possible to define our own Functional Interface? What is @FunctionalInterface? What are the rules to define a Functional Interface?
  • Is @FunctionalInterface annotation mandatory to define a Functional Interface? What is the use of @FunctionalInterface annotation? Why do we need Functional Interfaces in Java?
  • When do we go for Java 8 Stream API? Why do we need to use Java 8 Stream API in our projects?
  • What is Spliterator in Java SE 8?Differences between Iterator and Spliterator in Java SE 8?

Set of Top 10 Java 8 Interview Questions and Answers To Learn in 2020

Source: (educba.com)

Guide to Java 8 Interview Questions. Here we have covered the most asked interview questions with their detailed answers to help crack interview with ease.

Outline:

  • Java 8 Interview Questions
  • Recommended Articles
  • What’s New in Java 8?

Free Interviewing Skills Tutorial – Java 8 Interview Questions Preparation Course

Source: (udemy.com)

Learn Top 50 Interview Questions on Java 8. Get Success in your Interview. – Free Course

Outline:

  • Description
  • What is the biggest benefit of this course to me?
  • What are the topics covered in this course?
  • How will this course help me?
  • Are there answers in this course?
  • What is the best way of viewing this course?
  • What is the level of questions in this course?

Free Online Course: Java 8 Interview Questions Preparation Course from Udemy

Source: (classcentral.com)

Learn Top 50 Interview Questions on Java 8. Get Success in your Interview.

Outline:

  • 157K Courses, 425M Enrollments: Breaking Down Udemy’s Massive Catalog
  • Latest
  • Overview
  • What is the biggest benefit of this course to me?
  • What are the topics covered in this course?
  • How will this course help me?
  • Are there answers in this course?
  • What is the best way of viewing this course?
  • What is the level of questions in this course?

Java 8 Interview Questions – Tutorialspoint

Source: (tutorialspoint.com)

Java 8 Interview Questions – Dear readers, these Java 8 Interview Questions have been designed specially to get you acquainted with the nature of questions you may encounter during your int

Outline:

  • What are the characteristics of a Java 8 lambda expression?
  • System.out::println method is a static method reference to println method of out object of System class. What are functional interfaces?
  • It represents an operation that accepts two input arguments, and returns no result. What is the purpose of BiFunction<T,U,R> functional interface?
  • Stream represents a sequence of objects from a source, which supports aggregate operations. What is stream pipelining in Java 8?
  • Stream has provided a new method ‘forEach’ to iterate each element of the stream. How will you print 10 random numbers using forEach of java 8?
  • The ‘map’ method is used to map each element to its corresponding result. How will you print unique squares of numbers in java 8?
  • The ‘filter’ method is used to eliminate elements based on a criteria. How will you print count of empty strings in java 8?
  • The ‘limit’ method is used to reduce the size of the stream. How will you print 10 random numbers in java 8?
  • The ‘sorted’ method is used to sort the stream. How will you print 10 random numbers in a sorted order in java 8?
  • How will you get the sum of all numbers present in a list using Java 8?
  • For Nashorn engine, JAVA 8 introduces a new command line tool, jjs, to execute javascript codes at console. Can you execute javascript code from java 8 code base?
  • What is Next?

Java 8 Interview Questions and Example Answers

Source: (indeed.com)

Read more to discover Java 8 interview questions with example answers to help you prepare for your next Java interview.

Outline:

  • General questions
  • Questions about Java development experience and background
  • Java 8 In-depth questions
  • Common Java 8 interview questions and answers
  • What are some important features of the Java 8 release?
  • What is a method reference in Java 8?
  • What are the characteristics of the Lambda expression in Java 8?
  • What’s the purpose of the Lambda expression?
  • What is a SAM interface?
  • What are the defining rules of a functional interface?
  • What are collectors and statistics collectors?
  • Explain Optional in Java 8?