Java 8 interview questions

Java 8 Interview Questions(+ Answers)

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

learning-zone/java-interview-questions

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?

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?