80+ Interview Questions and Answers

Two ways to write a sentence in mirror image form in Java: reverse string function and array conversion.

• Use the reverse() method of the String class to reverse the sentence

• Convert the sentence to a character array, then swap the first and last characters, second and second-to-last characters, and so on until the middle is reached

• Example: 'Hello World' becomes 'dlroW olleH'

Java 8 introduced streams which are more efficient than collections in certain cases.

• Streams are useful for processing large amounts of data in parallel

• Collections are better for small amounts of data or when modifying data

• Java 8's stream API provides a functional programming approach to data processing

• Java 7's collections API is more traditional and imperative

• Example: Using streams to filter and map data from a database query

• Example: Using collections to manipulate a small l...read more

The question asks for programs on Java 8 and 11, multithreading, collections, design patterns, SOLID principles, Spring MVC and Boot, and REST API.

• Java 8 and 11 programs: Provide examples of programs written in Java 8 and 11.

• Multithreading: Discuss the concept of multithreading and provide examples of how it can be implemented in Java.

• Collections: Explain the different types of collections in Java and their usage.

• Design patterns: Discuss commonly used design patterns in softw...read more

Abstract classes, interfaces, and enums provide abstraction and modularity in Java.

• Abstract classes provide a partial implementation of a class and cannot be instantiated.

• Interfaces define a set of methods that a class must implement and can be used for multiple inheritance.

• Enums provide a set of named constants.

• All three are used for abstraction and modularity in Java.

• Abstract classes and interfaces are used for polymorphism and code reuse.

• Enums are used for defining a fixed...read more

Object-oriented software engineering is a framework for designing and developing software using objects.

• Object-oriented software engineering is a methodology for designing and developing software using objects.

• It involves creating classes and objects that encapsulate data and behavior.

• Frameworks are pre-built structures that provide a foundation for building software applications.

• Frameworks can include libraries, APIs, and other tools that simplify the development process.

• Exa...read more

ADBMS stands for Advanced Database Management System which is an extension of DBMS with additional features.

• ADBMS has advanced features like data mining, data warehousing, and online analytical processing.

• ADBMS is used for handling large and complex data sets.

• DBMS is a basic system for managing data and is used for small and simple data sets.

• DBMS does not have advanced features like ADBMS.

• Examples of ADBMS are Oracle, IBM DB2, and Microsoft SQL Server.

• Examples of DBMS are MyS...read more

Static is used in public static void main to allow the method to be called without creating an instance of the class.

• Static methods belong to the class and not to any instance of the class.

• The main method is the entry point of a Java program and needs to be called without creating an object of the class.

• The static keyword allows the main method to be called directly from the class, without creating an instance of the class.

• The main method signature is public static void main(...read more

Use lambda function to print greater number

• Define a lambda function that takes two parameters

• Use the max() function inside the lambda to compare the two numbers

• Call the lambda function with two numbers to print the greater one

Program to count characters in a string and sort an array without using sort method

• Use a loop to iterate through the string and count each character

• For sorting an array, use a loop to compare each element with all other elements and swap if necessary

• Implement a sorting algorithm like bubble sort, insertion sort or quick sort

Use two threads to print numbers 1-10 in correct order

• Create two threads, one for printing odd numbers and one for printing even numbers

• Use synchronization mechanisms like mutex or semaphore to ensure correct order

• Example: Thread 1 prints 1, 3, 5, 7, 9 and Thread 2 prints 2, 4, 6, 8, 10

Add one to a given String of number

• Convert the string to integer, add one, and convert back to string

• Handle edge cases like leading zeros

• Consider using built-in functions like parseInt() and toString()

I have worked with design patterns such as Singleton, Factory, Observer, and Strategy in my projects.

• Singleton pattern was used to ensure only one instance of a class is created.

• Factory pattern was used to create objects without specifying the exact class of object that will be created.

• Observer pattern was used to define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.

• Strategy pattern wa...read more

Use git bisect command to find the commit that caused the build failure

• Use 'git bisect start' to start the bisect process

• Mark the current commit as bad with 'git bisect bad'

• Mark a known good commit with 'git bisect good '

• Git will automatically checkout commits for testing, mark them as good or bad until the culprit commit is found

Fibonacci series code in iterative and recursive methods

• Iterative method: Use a loop to calculate Fibonacci numbers

• Recursive method: Define a function that calls itself to calculate Fibonacci numbers

• Example for iterative method: int fib(int n) { int a = 0, b = 1, c; for(int i = 2; i <= n; i++) { c = a + b; a = b; b = c; } return b; }

• Example for recursive method: int fib(int n) { if(n <= 1) return n; return fib(n-1) + fib(n-2); }

Index is a database structure that improves the speed of data retrieval. Types include clustered, non-clustered, and full-text.

• Index is a data structure that improves query performance by allowing faster data retrieval.

• Clustered index determines the physical order of data in a table.

• Non-clustered index is a separate structure that stores a copy of the indexed columns and a pointer to the actual data.

• Full-text index is used for text-based searches and allows for complex querie...read more

To add a dynamic component in a view, use a framework or library that supports dynamic rendering and component creation.

• Use a framework like React or Angular that allows for dynamic component creation

• Create a component factory or use a component resolver to dynamically create and render components

• Pass data or props to the dynamic component to customize its behavior

• Update the view or component tree to include the dynamically created component

Normalization is a process of organizing data in a database to reduce redundancy and dependency.

• Normalization is used to eliminate data redundancy and improve data integrity.

• It involves dividing a database into two or more tables and defining relationships between them.

• There are different levels of normalization, such as first normal form (1NF), second normal form (2NF), and so on.

• Normalization helps in efficient data retrieval and reduces the chances of data inconsistencies....read more

Call stack is a data structure that stores function calls in JavaScript, while event loop manages asynchronous operations.

• Call stack is a mechanism for managing function invocation in JavaScript.

• Functions are added to the call stack when they are invoked and removed when they are completed.

• Event loop is responsible for handling asynchronous operations in JavaScript.

• Event loop continuously checks the call stack and the callback queue to determine if there are any tasks to be e...read more

Concurrent Utility Classes provide support for concurrent programming in Java.

• ConcurrentHashMap: Thread-safe implementation of Map interface.

• CopyOnWriteArrayList: Thread-safe implementation of List interface.

• CountDownLatch: Synchronization aid that allows one or more threads to wait until a set of operations being performed in other threads completes.

• Semaphore: Controls the number of threads that can access a shared resource concurrently.

• ExecutorService: Interface that provid...read more

Transaction propagation in Hibernate allows the management of multiple database operations within a single transaction.

• Hibernate supports different transaction propagation modes such as REQUIRED, REQUIRES_NEW, SUPPORTS, MANDATORY, NOT_SUPPORTED, and NEVER.

• The propagation mode determines how the transaction should be handled when a method is called within an existing transaction.

• REQUIRED is the default propagation mode, where if a transaction exists, the method will join it, o...read more

Core Java features in Java 8 include lambda expressions, functional interfaces, streams, and default methods.

• Lambda expressions allow you to pass functionality as an argument to a method.

• Functional interfaces have a single abstract method and can be used with lambda expressions.

• Streams provide a way to process collections of objects in a functional style.

• Default methods allow interfaces to have methods with implementations.

• Example: Using lambda expressions to iterate over a l...read more

CompletableFuture is a class introduced in Java 8 to represent a future result of an asynchronous computation.

• CompletableFuture can be used to perform tasks asynchronously and then combine their results.

• It supports chaining of multiple asynchronous operations.

• It provides methods like thenApply, thenCompose, thenCombine, etc. for combining results.

• Example: CompletableFuture future = CompletableFuture.supplyAsync(() -> 10);

OOPs concept is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• OOPs stands for Object-Oriented Programming

• It focuses on creating objects that interact with each other to solve a problem

• Encapsulation, inheritance, polymorphism, and abstraction are key principles of OOPs

• HashMap in Java is a data structure that stores key-value pairs

• It uses hashing to store and retrieve elements efficiently

• E...read more

Yes, I am able to work in hybrid mode which involves a combination of remote and on-site work.

• Experienced in collaborating with remote team members using communication tools like Slack, Zoom, and Jira

• Comfortable with switching between working on-site and remotely based on project requirements

• Adaptable to different work environments and able to maintain productivity in both settings

Agile ceremonies are key meetings in Agile methodology where QA plays a crucial role in ensuring quality throughout the development process.

• QA participates in Agile ceremonies such as Sprint Planning, Daily Stand-ups, Sprint Review, and Sprint Retrospective to provide input on quality aspects.

• QA helps in defining acceptance criteria for user stories during Sprint Planning to ensure that the team understands the quality expectations.

• QA collaborates with developers during Daily...read more

Updating the scrum board involves adding, moving, and removing tasks to reflect the current status of the project.

• Regularly update the scrum board with the progress of tasks

• Move tasks from 'To Do' to 'In Progress' to 'Done' columns as they are worked on and completed

• Remove tasks that are no longer relevant or have been completed

• Ensure the team is aware of any changes made to the scrum board

ACID properties are a set of properties that ensure database transactions are processed reliably.

• ACID stands for Atomicity, Consistency, Isolation, and Durability.

• Atomicity ensures that a transaction is treated as a single, indivisible unit of work.

• Consistency ensures that a transaction brings the database from one valid state to another.

• Isolation ensures that concurrent transactions do not interfere with each other.

• Durability ensures that once a transaction is committed, it ...read more

Java is an object-oriented language with features like inheritance, encapsulation, and polymorphism.

• Inheritance allows classes to inherit properties and methods from other classes.

• Encapsulation hides the implementation details of a class from other classes.

• Polymorphism allows objects to take on multiple forms or behaviors.

• Java also supports abstraction, interfaces, and exception handling.

• Example: class Car extends Vehicle, interface Drawable, try-catch block for exception han...read more

OOPs concepts refer to Object-Oriented Programming principles like inheritance, encapsulation, polymorphism, and abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability to present the same interface for different data types.

• Abstraction: Hiding the complex implementation details and showing only the necessary features.

Unit testing in C++ involves writing test cases for individual units of code to ensure they work as expected.

• Use a unit testing framework like Google Test or Catch2 to write and run test cases

• Create separate test files for each unit of code being tested

• Use assertions to check the expected behavior of the code under test

• Mock dependencies or use dependency injection to isolate units for testing

• Run tests regularly to catch regressions and ensure code quality

Aggregation functions are used to perform calculations on groups of data in a database.

• Aggregation functions include COUNT, SUM, AVG, MAX, and MIN.

• They are used with the GROUP BY clause to group data based on a specific column.

• COUNT function returns the number of rows in a table or the number of non-null values in a column.

• SUM function returns the sum of values in a column.

• AVG function returns the average of values in a column.

• MAX function returns the maximum value in a colum...read more

JDK 8 features include lambda expressions, functional interfaces, streams, and default methods.

• Lambda expressions allow you to write code in a more concise and readable way.

• Functional interfaces enable the use of lambda expressions.

• Streams provide a way to work with sequences of elements efficiently.

• Default methods allow interfaces to have concrete methods.

• Date and Time API improvements.

Deep copy creates a new object and recursively copies all nested objects, while shallow copy creates a new object and copies the references to nested objects.

• Deep copy duplicates all levels of the object hierarchy, ensuring that changes in the copied object do not affect the original object.

• Shallow copy only duplicates the top-level object, so changes in the copied object may affect the original object.

• Deep copy is more time and memory-consuming than shallow copy.

• In Python, d...read more

Ways to set values in form groups

• Use setValue() method to set values in form groups

• Use patchValue() method to set values in form groups

• Use reset() method to set values in form groups

To design a high-performance Cache API for multithreaded environment, follow these pointers:

• Use a concurrent hash map to store the cache data

• Implement a read-write lock to allow multiple threads to read simultaneously

• Use a thread-safe data structure for cache eviction policy

• Implement a cache loader to load data into the cache on demand

• Use a bounded cache to prevent memory overflow

• Implement a cache statistics collector to monitor cache usage

• Use a cache manager to manage the ca...read more

Story estimation techniques in Agile involve using relative sizing, planning poker, and t-shirt sizing.

• Relative sizing compares the size of one story to another to estimate effort.

• Planning poker involves team members individually estimating stories and then discussing differences.

• T-shirt sizing categorizes stories into small, medium, large, etc. based on complexity.

• Fibonacci sequence can be used for story points (1, 2, 3, 5, 8, 13, etc.).

Inheritance is a concept in object-oriented programming where a class inherits properties and behaviors from another class.

• Inheritance allows a class to reuse code from another class, promoting code reusability and reducing redundancy.

• Subclasses can inherit attributes and methods from a superclass, and can also override or extend them.

• Inheritance creates a hierarchical relationship between classes, with child classes inheriting from parent classes.

• Example: A 'Vehicle' class c...read more

Microservice architecture focuses on breaking down applications into smaller, independent services.

• Microservices are small, independent services that work together to form a complete application.

• Each microservice is responsible for a specific function or feature.

• Design patterns like API Gateway, Circuit Breaker, and Service Registry are commonly used in microservice architecture.

• Microservices communicate with each other through APIs.

• Scalability, fault tolerance, and flexibili...read more

Java is an object-oriented language while C is a procedural language.

• Java is platform-independent while C is platform-dependent.

• Java has automatic garbage collection while C requires manual memory management.

• Java has built-in support for multithreading while C requires external libraries.

• Java has a larger standard library compared to C.

• Java is more secure than C due to its strong type checking and exception handling.

• C is faster than Java in terms of execution speed.

• C is commo...read more

Method references in Java 8 are a way to refer to methods or constructors without invoking them directly.

• Method references are shorthand notation for lambda expressions.

• They can be used to make code more concise and readable.

• There are four types of method references: static, instance, constructor, and arbitrary object.

• Example: list.forEach(System.out::println);

A program to check the occurrence of words in a paragraph.

• Split the paragraph into words using space as delimiter

• Create a hashmap to store word frequencies

• Iterate through the words and update the hashmap accordingly

• Display the word frequencies

Promises are used for a single async operation while observables are used for multiple async operations and can be cancelled.

• Promises are eager, meaning they start immediately upon creation.

• Observables are lazy, meaning they only start when subscribed to.

• Promises can only handle a single value or error, while observables can handle multiple values over time.

• Observables can be cancelled, while promises cannot.

• Promises are part of ES6, while observables are part of RxJS library...read more

SQL Joins are used to combine rows from two or more tables based on a related column between them.

• INNER JOIN: Returns rows when there is at least one match in both tables

• LEFT JOIN: Returns all rows from the left table and the matched rows from the right table

• RIGHT JOIN: Returns all rows from the right table and the matched rows from the left table

• FULL JOIN: Returns rows when there is a match in one of the tables

I completed my polytechnic from XYZ College.

• I pursued my polytechnic studies from XYZ College.

• I gained valuable knowledge and skills in engineering from my college.

• My college provided me with hands-on experience through practical sessions and projects.

• I was able to network with industry professionals and alumni through various events organized by my college.

Oops concepts in java refer to Object-Oriented Programming principles like Inheritance, Encapsulation, Polymorphism, and Abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability of a method to do different things based on the object it is acting upon.

• Abstraction: Hiding the implementation details and showing only the necessary feature...read more

Caching is the process of storing data in a temporary storage area to reduce access time and improve performance.

• Caching helps in speeding up data retrieval by storing frequently accessed data closer to the user.

• It reduces the need to access the original source of data, saving time and resources.

• Examples of caching include browser caching, CDN caching, and database caching.

Yes, I have knowledge in Autocad.

• I have experience in creating 2D and 3D drawings using Autocad.

• I am proficient in using Autocad tools such as layers, blocks, and dimensions.

• I have used Autocad for designing mechanical parts and assemblies.

• I am familiar with Autocad's interface and commands.

No, @FunctionalInterface cannot be extended. Map and flatMap are default methods in the interface and cannot be overridden.

• No, @FunctionalInterface cannot be extended as it is a single abstract method interface.

• Map and flatMap are default methods in the interface and cannot be overridden.

• Example: public interface MyInterface { void myMethod(); default void myDefaultMethod() { // implementation } }

Enhancements can be categorized into three types: functional, technical, and performance.

• Functional enhancements improve the functionality of the system.

• Technical enhancements improve the technical aspects of the system.

• Performance enhancements improve the performance of the system.

• Examples of functional enhancements include adding new features or improving existing ones.

• Examples of technical enhancements include upgrading hardware or software components.

• Examples of performan...read more

BADi is a Business Add-In that allows customizations to SAP applications. BAPI is a Business Application Programming Interface for SAP.

• BADi is used to enhance the functionality of SAP applications without modifying the source code.

• BAPI is used to integrate SAP applications with other systems.

• BADi is implemented using ABAP code.

• BAPI is a set of standard interfaces for accessing SAP business objects.

• Examples of BADi include enhancing the functionality of SAP Sales and Distribut...read more

HashMap is a data structure that stores key-value pairs and uses hashing to quickly retrieve values based on keys.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to determine the index in the array where it will be stored.

• If multiple keys hash to the same index, a linked list is used to handle collisions.

• HashMap uses the hashCode() method of keys to calculate the hash value.

• HashMap provides constant-t...read more

I have experience using a variety of testing tools such as Selenium, Jira, and TestRail.

• Selenium

• Jira

• TestRail

Deep dive into .NET Core and Angular

• NET Core is a cross-platform, open-source framework for building modern, cloud-based, internet-connected applications.

• Angular is a popular front-end framework for building dynamic web applications.

• Understanding the architecture, features, and best practices of both .NET Core and Angular is essential for developing robust and scalable applications.

• Integration of .NET Core backend with Angular frontend for creating full-stack applications.

• Uti...read more

Temp tables are used to store temporary data during a session. There are two types: local and global.

• Local temp tables are only accessible within the session that created them.

• Global temp tables are accessible to all sessions and are prefixed with ##.

• Temp tables are automatically dropped when the session that created them ends.

• Temp tables can improve performance by reducing the need for expensive queries or joins.

Query optimization involves identifying and improving the performance of database queries.

• Identify slow queries using profiling tools

• Analyze query execution plans to identify bottlenecks

• Optimize queries by rewriting them or adding indexes

• Use caching to reduce the number of queries

• Regularly monitor and tune the database for optimal performance

Iterate through the array to find the second greatest number.

• Iterate through the array and keep track of the greatest and second greatest numbers.

• Compare each element with the current greatest and second greatest numbers.

• Update the second greatest number if a new number is found that is greater than the current second greatest but less than the greatest.

The shortcut key for circle is 'O'

• Press 'O' key to draw a circle in most design software

• Can be used in Adobe Illustrator, AutoCAD, SketchUp, etc.

RFPs are Requests for Proposals used to solicit bids from vendors for a project or service.

• RFPs outline project requirements, timelines, and evaluation criteria

• They are used in procurement processes to select the best vendor

• Commonly used in industries like construction, IT, and consulting

• Examples include government agencies issuing RFPs for infrastructure projects

An automation framework consists of a set of guidelines, coding standards, and best practices to automate testing.

• The framework should be modular and scalable

• It should have a clear separation of concerns

• It should have reusable components such as libraries, functions, and utilities

• It should have a reporting mechanism to track test results

• It should support multiple test types such as functional, regression, and performance testing

• Examples of popular automation frameworks includ...read more

The shortcut key for line is Ctrl+L.

• Press Ctrl+L to draw a straight line in most design software.

• The line tool can be found in the toolbar of most design software.

• Lines can be customized by adjusting their thickness, color, and style.

Inheritance is a mechanism in object-oriented programming where a class acquires the properties of another class.

• Inheritance allows for code reusability and promotes a hierarchical organization of code.

• The class that is being inherited from is called the superclass or parent class, while the class that inherits is called the subclass or child class.

• The subclass can access all the public and protected methods and variables of the superclass.

• For example, a class Animal can be a...read more

Use a sorting algorithm like bubble sort or quicksort to arrange elements in ascending order.

• Use a sorting algorithm like bubble sort, quicksort, or merge sort to rearrange elements in ascending order.

• For example, you can implement bubble sort to compare adjacent elements and swap them if they are in the wrong order.

• Another example is using quicksort to divide the array into smaller subarrays and recursively sort them.

Designing and analyzing a project involves creating a plan and evaluating its feasibility and effectiveness.

• Identify project goals and objectives

• Develop a detailed project plan including timelines and resources

• Conduct risk analysis and mitigation strategies

• Evaluate project outcomes and make adjustments as needed

Business Analysts analyze business processes and systems to provide solutions for improvement. SQL knowledge is often required.

• Business Analysts gather and analyze data to understand business needs and requirements

• They work with stakeholders to define project scope and objectives

• BA create detailed documentation of requirements and solutions

• SQL knowledge is beneficial for querying databases and analyzing data

A Business Analyst (BA) analyzes business processes, identifies needs, and recommends solutions. SQL is a programming language used for managing and querying databases.

• BA analyzes business processes to identify needs and recommend solutions

• BA works closely with stakeholders to gather requirements and define project scope

• SQL is a programming language used for managing and querying databases

• SQL allows users to retrieve and manipulate data stored in a database

• BA may use SQL to e...read more

Root cause analysis is a systematic process used to identify the underlying cause of a problem or issue.

• Identify the problem or issue

• Gather data and evidence related to the problem

• Analyze the data to determine the root cause

• Develop solutions to address the root cause

• Implement and monitor the effectiveness of the solutions

Spring MVC is a framework for building web applications in Java.

• Spring MVC is a part of the Spring Framework, which provides a model-view-controller architecture for developing web applications.

• It follows the MVC design pattern, where the model represents the data, the view represents the user interface, and the controller handles the requests and manages the flow of data.

• It provides features like request mapping, data binding, validation, and view resolution.

• Example: In a Sp...read more

Pipes in Angular are used to transform data in templates.

• Pipes are used to format data before displaying it in the view.

• They can be used to filter, sort, or manipulate data in various ways.

• Examples include currency, date, uppercase, and lowercase pipes.

Testing is the process of evaluating a system or its component(s) with the intent to find whether it satisfies the specified requirements or not.

• Testing is done to identify defects or errors in software

• It involves executing a system or application with the intent of finding bugs

• Testing can be done manually or through automated tools

• Types of testing include functional, performance, security, and usability testing

End to end project flow involves planning, execution, monitoring, and closing of a project.

• Initiation: Define project scope, objectives, and deliverables.

• Planning: Create project plan, schedule, and budget.

• Execution: Implement project plan and deliver project deliverables.

• Monitoring: Track project progress, identify risks, and make necessary adjustments.

• Closing: Finalize project deliverables, obtain client approval, and close out project.

Microservices can introduce complexity, communication overhead, and potential performance issues.

• Increased complexity due to managing multiple services

• Communication overhead between services

• Potential performance issues due to network latency

• Difficulty in maintaining consistency across services

Scrum Agile is a framework for managing and completing complex projects in an iterative and incremental manner.

• Scrum is based on the principles of transparency, inspection, and adaptation.

• It involves breaking down the project into smaller tasks called user stories.

• Teams work in short iterations called sprints, usually 2-4 weeks long.

• Daily stand-up meetings are held to discuss progress and any obstacles.

• Scrum roles include Product Owner, Scrum Master, and Development Team.

• Popu...read more

Devops tools are software products that help automate the processes involved in software development, testing, and deployment.

• Popular Devops tools include Jenkins, Docker, Ansible, Kubernetes, and Git.

• These tools help in automating tasks like building, testing, and deploying software applications.

• They also facilitate collaboration between development and operations teams, leading to faster and more reliable software delivery.

• Devops tools are often used in conjunction with con...read more

Java has two types of beans: stateful and stateless beans.

• Stateful beans maintain conversational state with the client, while stateless beans do not.

• Stateful beans are typically used for long-running conversations, while stateless beans are used for short-lived operations.

• Examples of stateful beans include session beans, while examples of stateless beans include message-driven beans.

WFM process involves forecasting, scheduling, real-time management, and reporting to optimize workforce efficiency.

• Forecasting: predicting future workload and staffing needs

• Scheduling: creating employee schedules based on forecasted needs

• Real-time management: monitoring and adjusting schedules in real-time

• Reporting: analyzing data to improve future forecasting and scheduling

• Examples: call center staffing, retail store scheduling, healthcare staffing

Multithreading in Java allows multiple threads to execute concurrently, improving performance and responsiveness.

• Multithreading is achieved by extending the Thread class or implementing the Runnable interface.

• Threads share the same memory space but have their own program counter, stack, and local variables.

• Java provides synchronized keyword and locks to prevent data corruption in multithreaded environments.

• Example: Creating a new thread - Thread thread = new Thread(new MyRunn...read more

Lambdas in Java are anonymous functions that allow you to pass behavior as an argument to a method.

• Lambdas are used to implement functional interfaces with a single abstract method.

• They provide a concise way to write code by reducing boilerplate.

• Syntax: (parameters) -> expression or statement block

• Example: (int a, int b) -> a + b

SQL join tables to combine data from multiple tables based on a related column

• Use JOIN keyword to combine tables based on a related column

• Types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

• Specify the columns to join on using ON clause

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id

Devops tools are essential for automation, collaboration, and monitoring in the software development lifecycle.

• Devops tools help automate tasks like code deployment, infrastructure provisioning, and testing.

• Popular Devops tools include Jenkins, Docker, Ansible, Kubernetes, and Git.

• These tools facilitate collaboration between development and operations teams, enabling faster delivery of software.

• Monitoring tools like Nagios, Prometheus, and ELK stack help ensure the stability ...read more