Java
Understanding the JVM
JVM What Does the JVM Do? Classloader Runtime Data Areas Frames Execution Engine Useful Links What Does the JVM Do? Loads, verifies, and executes bytecode; Provides a runtime environment for executing bytecode; Manages memory and performs garbage collection; The Java Virtual Machine (JVM) is a mechanism that provides a runtime environment for managing Java code or applications. It is an independent execution shell for code, enabling it to run on any operating system without the operating system affecting the executing program.
Interview Questions for Java 8
Interview Questions for Java 8 What new features were introduced in Java 8 and JDK 8? What is a “lambda”? What is the structure and unique characteristics of using a lambda expression? What variables can lambda expressions access? How can you sort a list of strings using a lambda expression? What is a “method reference”? What types of method references do you know? Explain the expression System.out::println. What are “functional interfaces”?
JDBC Interview Questions
JDBC What is JDBC? What are the advantages of using JDBC? What is a JDBC URL? What components make up JDBC? List the main classes and interfaces in JDBC. Describe the main steps for working with the database using JDBC. List the main data types used in JDBC. How are they related to Java types? How do you register a JDBC driver? How do you establish a connection to a database?
Understanding Serialization in Java
A comprehensive guide to understanding serialization in Java, including key concepts and best practices.
Java Collections Framework
Interview Questions Java Collections Framework What is a “collection”? Name the main interfaces of the JCF and their implementations. Arrange the following interfaces in a hierarchy: List, Set, Map, SortedSet, SortedMap, Collection, Iterable, Iterator, NavigableSet, NavigableMap. Why is Map not a Collection, while List and Set are Collection? What is the difference between java.util.Collection and java.util.Collections? What is “fail-fast behavior”? What is the difference between fail-fast and fail-safe? Provide examples of iterators that implement fail-safe behavior.
Input/Output Streams in Java
Input/Output Streams in Java What is the difference between IO and NIO? What NIO features do you know? What are “channels”? What types of input/output streams exist? Name the main classes of input/output streams. In which packages are the classes for input/output streams located? What subclasses of the InputStream class do you know, and what are they for? What is PushbackInputStream used for? What is SequenceInputStream used for? Which class allows reading data from an input byte stream in the format of primitive data types?
Java Concurrency Interview Questions
Interview Questions Multithreading Tell us about the Java memory model? What is “thread safety”? What is the difference between “concurrency” and “parallelism”? What is “cooperative multitasking”? What type of multitasking does Java use? What is the reasoning behind this choice? What are ordering, as-if-serial semantics, sequential consistency, visibility, atomicity, happens-before, mutual exclusion, safe publication? What is the difference between a process and a thread? What are “green threads,” and does Java have them?
Java Core Interview Questions
Interview Questions Java Core What are the differences between JRE, JVM, and JDK? What access modifiers exist? What does the final keyword indicate? What are the default values for uninitialized variables? What do you know about the main() function? What logical operations and operators do you know? What is the ternary conditional operator? What bitwise operations do you know? Where and for what is the abstract modifier used? Define the term “interface”.