100+ Interview Questions and Answers

Find 2nd largest element in an array with repeated elements in O(n) complexity.

• Traverse the array once and keep track of the largest and second largest elements.

• If the current element is greater than the largest element, update both largest and second largest elements.

• If the current element is between the largest and second largest elements, update only the second largest element.

Two programming code examples in any language

• Example 1: Python - print('Hello, World!')

• Example 2: Java - System.out.println('Hello, World!')

Node.js is a server-side JavaScript runtime environment.

• Node.js is built on top of the V8 JavaScript engine from Google Chrome.

• It allows developers to write server-side code in JavaScript.

• Node.js has a non-blocking I/O model, making it efficient for handling large amounts of data.

• Node.js has a vast library of modules available through npm (Node Package Manager).

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.

• To retrieve a value, the key is hashed again to find the corresponding index and then the linked l...read more

let, var, and const are all used to declare variables in JavaScript, but they have different scoping rules and behaviors.

• let and const were introduced in ES6, while var has been around since the beginning of JavaScript.

• let and const are block-scoped, while var is function-scoped.

• Variables declared with const cannot be reassigned, while let and var can be.

• const variables must be initialized when they are declared, while let and var can be declared without initialization.

• Exampl...read more

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

• Joins are used to retrieve data from multiple tables based on a related column

• Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

• 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...read more

Pillars of OOP are Inheritance, Encapsulation, Abstraction, and Polymorphism.

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

• Encapsulation restricts access to certain components of an object, protecting its integrity.

• Abstraction hides complex implementation details and only shows the necessary features.

• Polymorphism allows objects to be treated as instances of their parent class or their own class.

Express.js is a popular Node.js web framework used for building web applications. Body-parser is a middleware used to parse incoming request bodies.

• Express.js is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.

• It provides a way to handle HTTP requests and responses, routing, middleware, and more.

• Body-parser is a middleware used to parse incoming request bodies in a middleware before your handlers,...read more

Scopes in JavaScript determine the accessibility of variables and functions.

• Global scope: variables and functions declared outside any function are accessible globally

• Local scope: variables and functions declared inside a function are only accessible within that function

• Block scope: variables declared with let and const are only accessible within the block they are declared in

• Function scope: variables declared with var are accessible within the function they are declared in

Callback hell is a situation where nested callbacks make code unreadable. Promises are a solution to this problem.

• Callback hell occurs when there are too many nested callbacks in asynchronous code

• It makes the code difficult to read and maintain

• Promises are a way to handle asynchronous operations without nested callbacks

• Promises can be used to chain multiple asynchronous operations together

• Promises have a resolve and reject function to handle success and failure respectively

Passport.js is an authentication middleware for Node.js.

• Passport.js provides a simple way to authenticate users with various authentication strategies such as local, OAuth, OpenID, etc.

• It is highly customizable and can be integrated with any Node.js web application framework.

• Passport.js maintains user sessions and provides a consistent API for authentication across different strategies.

• Example: Using Passport.js with Express.js to authenticate users with Google OAuth2.

• Example...read more

Interview questions for Project Lead position covering API testing, HTTP error codes, performance testing, Java, authentication, Swagger, AWS, and project-related questions.

• API testing involves testing the functionality, reliability, performance, and security of APIs.

• HTTP error codes are status codes returned by a server to indicate the status of a request.

• APIs can be tested using tools like Postman, SoapUI, and JMeter.

• Types of APIs include REST, SOAP, and GraphQL.

• Java and OO...read more

Event loop is a mechanism that allows JavaScript to perform non-blocking I/O operations.

• Event loop is a loop that constantly checks the message queue and executes the next message if there is any.

• Phases are the different stages of the event loop, such as timers, I/O callbacks, idle, and poll.

• Event loop is crucial for Node.js to handle multiple requests simultaneously without blocking the main thread.

• Example: setTimeout() function is added to the timer phase and executed after...read more

Python compiles source code to bytecode for faster execution, stored in .pyc files.

• Python interpreter compiles source code to bytecode before execution

• Bytecode is platform-independent and faster to execute than source code

• Compiled bytecode is stored in .pyc files for future use and faster startup time

• If source code is modified, .pyc files are automatically recompiled

Media query for 3 divs in row for desktop and column for mobile view

• Use min-width and max-width to target desktop and mobile views respectively

• Set display property to flex and flex-wrap to wrap for desktop view

• Set display property to block for mobile view

Function hoisting is a JavaScript behavior where function declarations are moved to the top of their scope.

• Function declarations are moved to the top of their scope during the compilation phase.

• Function expressions are not hoisted.

• Hoisting can lead to unexpected behavior and bugs if not understood properly.

Many-to-many relationship in Hibernate without common columns

• Create a third table with foreign keys to both tables

• Use @ManyToMany annotation in both entity classes

• Specify the join table name and column names in @JoinTable annotation

Arrow functions are a concise way to write functions in JavaScript.

• They have a shorter syntax than traditional function expressions.

• They do not have their own 'this' keyword.

• They are not suitable for methods, constructors, or prototype methods.

• Example: const add = (a, b) => a + b;

• Example: const square = x => x * x;

Node.js is single-threaded to optimize performance and simplify programming.

• Node.js uses an event-driven, non-blocking I/O model.

• This allows for efficient handling of multiple requests without creating new threads.

• Node.js also uses a single event loop to manage all I/O operations.

• This simplifies programming by eliminating the need for complex thread synchronization.

• However, Node.js can still take advantage of multi-core systems by creating child processes.

Using list comprehension and lambda function to manipulate a list of prime numbers

• Use list comprehension to generate a list of numbers

• Use a lambda function to check if a number is prime

• Filter the list of numbers using the lambda function to get prime numbers

Node is a runtime environment for executing JavaScript code, while Express is a web application framework built on top of Node.

• Node provides the platform for running JavaScript code outside of a web browser

• Express is a lightweight framework that simplifies building web applications on top of Node

• Express provides features like routing, middleware, and templating that make it easier to build web applications

• Node and Express are often used together to build scalable and efficien...read more

Find second largest integer in an array without sorting or using collections.

• Iterate through array and keep track of largest and second largest integers.

• Compare each element with current largest and second largest integers.

• Return second largest integer.

Loops, map, and list are fundamental concepts in programming.

• Loops are used to repeat a block of code until a certain condition is met.

• Map is a higher-order function that applies a given function to each element of a list and returns a new list.

• List is a collection of elements that can be accessed by their index.

• Example: for loop, map function, list comprehension.

Exposure to the product can be validated through hands-on experience, user feedback, market research, and data analysis.

• Hands-on experience with the product through development and testing

• User feedback from customers or internal stakeholders

• Market research to understand the competitive landscape and user preferences

• Data analysis of usage metrics, customer behavior, and product performance

• Examples: Conducting user interviews, A/B testing features, analyzing sales data

Print only values from a nested JS object

• Use Object.values() to get an array of values

• Recursively iterate through nested objects

• Filter out non-object values before iterating

The initial steps involve understanding the client requirements, analyzing the scope of work, and creating a plan for API development.

• Meet with the client to discuss their requirements and goals for the APIs

• Gather detailed information about the data and functionality that the APIs need to provide

• Analyze the scope of work and determine the resources and timeline needed for development

• Create a plan outlining the steps involved in API development, including design, implementatio...read more

PUT method updates data if available, else returns success with no changes.

• PUT method updates the resource if it exists, else creates a new resource

• If no data is provided, the server returns a success response with no changes made

• Example: PUT /users/1 with empty body will return success with no changes if user with id 1 exists

Difference between sort and sorted, dump vs dumps, load vs loads etc.

• sort() is a method of list object while sorted() is a built-in function

• dump() serializes an object to a file while dumps() serializes to a string

• load() deserializes an object from a file while loads() deserializes from a string

Use @PostConstruct annotation or implement CommandLineRunner interface

• Use @PostConstruct annotation on a method that needs to be executed on startup

• Implement CommandLineRunner interface and override run() method

• Add the code that needs to be executed on startup in the method annotated with @PostConstruct or in the run() method

• Example: @PostConstruct public void init() { //code to be executed on startup }

• Example: public class MyApp implements CommandLineRunner { public void run...read more

I would present the client with a detailed explanation of the design, highlighting its benefits and addressing any concerns they may have.

• Listen to the client's concerns and understand their perspective

• Explain the design concept clearly and address how it meets the client's needs

• Provide visual aids such as sketches or 3D models to help the client visualize the design

• Offer alternative solutions or compromises that may address the client's concerns while still maintaining the i...read more

Agile process involves iterative development, collaboration, and flexibility in responding to change.

• Agile process breaks down projects into smaller, manageable tasks called sprints.

• Teams work in short iterations, typically 2-4 weeks, to deliver working software.

• Regular meetings like daily stand-ups, sprint planning, and retrospectives help keep the team on track.

• Customer feedback is incorporated throughout the development process to ensure the final product meets their needs...read more

Microservices can communicate through synchronous or asynchronous protocols like REST, gRPC, or message brokers.

• Use RESTful APIs for synchronous communication

• Use message brokers like Kafka or RabbitMQ for asynchronous communication

• gRPC can be used for high-performance synchronous communication

• API Gateway can be used to manage communication between microservices

• Consider using service mesh like Istio or Linkerd for more advanced communication needs

Multithreading is the concurrent execution of multiple threads to achieve parallelism and improve performance.

• Multithreading allows multiple threads to run concurrently within a single process.

• Threads share the same memory space and resources of the process they belong to.

• Processes are independent instances of a program, each with its own memory space and resources.

• Processes do not share memory directly and communicate through inter-process communication (IPC).

• Threads are lig...read more

The OSI model has 7 layers. OSI or TCP/UDP depends on the application. OSI is used for theoretical understanding while TCP/UDP is used for practical implementation.

• The 7 layers of OSI model are Physical, Data Link, Network, Transport, Session, Presentation, and Application.

• OSI model is used for theoretical understanding of networking concepts.

• TCP/UDP are used for practical implementation of networking protocols.

• TCP is used for reliable data transfer while UDP is used for fast...read more

The @Service annotation is a specialization of the @Component annotation and is used to indicate that a class is a service.

• Both @Service and @Component annotations are used to indicate that a class is a Spring-managed component.

• @Service is a specialization of @Component and is used to indicate that a class is a service layer component.

• The @Service annotation is used to add a layer of abstraction between the controller and the DAO layer.

• The @Service annotation is used to provi...read more

Customization tools and details are essential for tailoring engineering solutions to specific needs.

• Customization tools allow for adjusting parameters to meet unique requirements

• Details provide a deeper understanding of the system being engineered

• Examples include CAD software for designing custom parts and simulation tools for optimizing performance

Custom middleware in .Net Core is required when we need to add additional processing logic to the request pipeline.

• Custom authentication

• Request logging

• Error handling

• Response compression

I have used multiple python modules for various purposes.

• I have used NumPy for numerical computations.

• I have used Pandas for data analysis and manipulation.

• I have used Matplotlib for data visualization.

• I have used Flask for web development.

• I have used Requests for making HTTP requests.

• I have used BeautifulSoup for web scraping.

• I have used Scikit-learn for machine learning tasks.

• I have used TensorFlow for deep learning tasks.

Extent report can be implemented by adding the extent report dependency, creating an instance of ExtentReports class, and using ExtentTest class to create test logs.

• Add the extent report dependency in the project's pom.xml file

• Create an instance of ExtentReports class in the @BeforeSuite method

• Create an instance of ExtentTest class in the @BeforeMethod method

• Use ExtentTest class to log test steps and results

• Generate the report using the flush() method in the @AfterSuite metho...read more

Creating SQL queries for different scenarios

• Use SELECT statement to retrieve data from a table

• Use WHERE clause to filter data based on specific conditions

• Use JOIN clause to combine data from multiple tables

HTTP error codes 400 and 500 represent client and server errors respectively.

• HTTP error code 400 indicates a client-side error, such as a bad request or invalid input.

• HTTP error code 500 indicates a server-side error, such as an internal server error or database connection issue.

• Other common client-side errors include 401 (unauthorized), 403 (forbidden), and 404 (not found).

• Other common server-side errors include 503 (service unavailable) and 504 (gateway timeout).

TSQL is a Microsoft proprietary extension of SQL used for querying and managing relational databases.

• TSQL stands for Transact-SQL and is used in Microsoft SQL Server.

• Optimization techniques in TSQL include indexing, query tuning, and avoiding unnecessary joins.

• Examples of optimization techniques in TSQL include using appropriate indexes on frequently queried columns and avoiding using functions in WHERE clauses.

SQL query to find the 2nd highest salary in a table

• Use the ORDER BY clause to sort the salaries in descending order

• Use the LIMIT clause to limit the result to the second row

• Consider handling cases where there might be ties for the highest salary

SQL query to find 2nd highest salary.

• Use ORDER BY to sort the salaries in descending order

• Use LIMIT to get the second highest salary

• Use subquery to avoid duplicates if multiple employees have the same salary

A program to read data from excel.

• Use a library like Apache POI or OpenPyXL to read excel files.

• Identify the sheet and cell range to read data from.

• Parse the data and store it in a suitable data structure.

• Handle errors and exceptions that may occur during the process.

Next.js is preferred over React.js for server-side rendering, automatic code splitting, and simplified routing.

• Next.js provides built-in support for server-side rendering, improving performance and SEO.

• Automatic code splitting in Next.js allows for faster page loads by only loading necessary code.

• Next.js simplifies routing with file-based routing, making it easier to organize and navigate between pages.

• Next.js also offers features like static site generation and API routes fo...read more

Python testing is a process of verifying the functionality of code. Unittest is a built-in testing framework in Python.

• Python testing is done to ensure that the code is working as expected.

• Unittest is a testing framework that comes with Python's standard library.

• It provides a set of tools for constructing and running tests.

• Tests are written as methods within a class that inherits from unittest.TestCase.

• Assertions are used to check if the expected output matches the actual out...read more

Lambda functions are anonymous functions that can be passed as arguments to other functions.

• Lambda functions are also known as anonymous functions because they don't have a name.

• They are often used as arguments to higher-order functions like map, reduce, and filter.

• Map applies a function to each element of an array and returns a new array with the results.

• Reduce applies a function to the elements of an array and returns a single value.

• Filter applies a function to each element...read more

SSIS packages are used for ETL processes in SQL Server. Union combines datasets vertically, while merge combines them horizontally.

• SSIS packages are used for Extract, Transform, Load (ETL) processes in SQL Server.

• Union in SSIS combines datasets vertically, stacking rows on top of each other.

• Merge in SSIS combines datasets horizontally, matching rows based on specified columns.

• Union All in SSIS combines datasets vertically without removing duplicates.

• Merge Join in SSIS combine...read more

Testing methodologies, defect life-cycle, high priority vs low severity defects, and Agile.

• Testing methodologies include black box, white box, and grey box testing.

• Defect life-cycle includes identification, logging, prioritization, fixing, retesting, and closure.

• High priority and low severity defect example: spelling mistake in a critical message.

• Low priority and high severity defect example: cosmetic issue in a non-critical area.

• Agile is an iterative and incremental approach...read more

Concurrent Hash Map is a thread-safe implementation of Hash Map.

• Uses multiple segments to allow concurrent access

• Each segment is a separate hash table with its own lock

• Segments are dynamically added or removed based on usage

• Uses CAS (Compare and Swap) operation for updates

• Provides higher concurrency than synchronized Hash Map

REST and SOAP are web service protocols with different design principles

• REST (Representational State Transfer) is an architectural style that uses standard HTTP methods like GET, POST, PUT, DELETE for communication

• SOAP (Simple Object Access Protocol) is a protocol that uses XML for message exchange and can work over various transport protocols like HTTP, SMTP, etc.

• REST is lightweight, scalable, and easy to use, while SOAP is more rigid and has built-in security features

• REST i...read more

A basic trigger code is used to automatically perform an action when a certain event occurs in a database.

• Triggers are written in SQL and can be used to enforce business rules, perform data validation, or maintain data integrity.

• Example: CREATE TRIGGER trigger_name BEFORE INSERT ON table_name FOR EACH ROW BEGIN ... END;

Data structures in Python: dict, tuple, list, set, string

• dict: unordered collection of key-value pairs

• tuple: ordered, immutable collection of elements

• list: ordered, mutable collection of elements

• set: unordered collection of unique elements

• string: ordered collection of characters

Object-oriented programming is a programming paradigm that uses objects to represent and manipulate data.

• Encapsulation: bundling data and methods together in a class

• Inheritance: creating new classes from existing ones

• Polymorphism: using a single interface to represent different types

• Abstraction: simplifying complex systems by breaking them into smaller, manageable parts

A composite primary key is a primary key that consists of two or more columns.

• A composite primary key is used when a single column cannot uniquely identify a record.

• It is created by combining two or more columns that together uniquely identify a record.

• Each column in a composite primary key must be unique and not null.

• Example: A table of orders may have a composite primary key consisting of order number and customer ID.

List slices are a way to extract a portion of a list by specifying start and end indices.

• List slices are denoted by using square brackets with start and end indices separated by a colon.

• The start index is inclusive and the end index is exclusive.

• If the start index is omitted, it defaults to 0. If the end index is omitted, it defaults to the length of the list.

• Negative indices can be used to count from the end of the list.

• List slices return a new list with the specified portio...read more

Automation framework is a set of guidelines, standards, and tools used for automating software testing.

• It provides a structured approach to automate tests

• It includes tools for test case management, test data management, and reporting

• It helps in reducing manual effort and increasing test coverage

• Examples include Selenium, Appium, and TestNG

Move all zeros in an array to the end while maintaining the order of other elements.

• Iterate through the array and move all zeros to the end while keeping the order of non-zero elements.

• Use two pointers approach to swap elements in-place.

• Example: Input [0, 1, 0, 3, 12], Output [1, 3, 12, 0, 0]

Spring Boot is designed to be a standalone application, so it can run without a separate server.

• Spring Boot includes an embedded server (like Tomcat or Jetty) so it can run independently.

• The embedded server is included in the application's JAR file, making it self-contained.

• This allows Spring Boot applications to be easily deployed and run without the need for a separate server installation.

Code programs to solve basic string manipulations

• Use built-in string functions like substring, replace, and split

• Implement algorithms for reversing a string, checking for palindromes, and counting occurrences of a character

• Handle edge cases like empty strings and null inputs

Ownership of the project approach refers to taking responsibility for the project's success and making decisions accordingly.

• The owner of the project approach should have a clear understanding of the project's goals and objectives.

• They should be able to make informed decisions about the project's direction and prioritize tasks accordingly.

• The owner should also be accountable for the project's success or failure and be willing to take corrective action when necessary.

• Effective...read more

Yes, but only if the list is immutable.

• Lists are mutable and cannot be used as dict keys.

• Tuples are immutable and can be used as dict keys.

• If a list needs to be used as a key, it can be converted to a tuple.

Yes, I have worked extensively on Java and Selenium.

• I have experience in developing and executing automated test scripts using Selenium WebDriver with Java.

• I have worked on various frameworks like TestNG, JUnit, and Cucumber for test automation.

• I have also integrated Selenium with other tools like Jenkins, Maven, and Git for continuous integration and delivery.

• I have experience in debugging and troubleshooting issues in Selenium scripts.

• I have worked on both web and mobile au...read more

let is block scoped, const is constant, var is function scoped

• let: block scoped, can be reassigned

• const: block scoped, cannot be reassigned, but its properties can be modified

• var: function scoped, can be reassigned

Java program to count frequency of characters in string

• Create a HashMap to store character and its frequency

• Convert the string to char array

• Iterate through the char array and update the frequency in HashMap

• Print the HashMap

Output of a Java program that extends a class and overrides a variable

• Class B extends Class A and overrides the variable num with a value of 100

• In the main method, an object of Class B is created and assigned to a reference variable of Class A

• When the value of num is accessed using the reference variable, the output will be 60 as it is the value of num in Class A

Quality Assurance process involves ensuring products meet standards and customer expectations.

• Developing quality standards and procedures

• Testing products to identify defects

• Implementing corrective actions

• Continuous monitoring and improvement

• Training staff on quality processes

Spring is a lightweight framework that provides comprehensive infrastructure support for developing Java applications.

• Spring works internally by using Inversion of Control (IoC) container to manage Java objects.

• It uses Dependency Injection to inject the dependencies of an object at runtime.

• Spring also provides Aspect-Oriented Programming (AOP) support for cross-cutting concerns.

• It utilizes various modules like Core, Context, AOP, JDBC, ORM, etc., to provide different function...read more

SQL injection is a type of cyber attack where malicious SQL code is inserted into input fields to manipulate a database.

• SQL injection occurs when a user input is not properly sanitized and allows an attacker to execute malicious SQL commands.

• It can lead to unauthorized access to sensitive data, data loss, and even complete server takeover.

• Example: Entering ' OR '1'='1' into a login form to bypass authentication and gain access to the system.

Drupal is a free and open-source content management system (CMS) used to create websites and web applications.

• Drupal is written in PHP and uses a MySQL or PostgreSQL database.

• It allows users to create and manage content, customize the appearance, and add functionality through modules.

• Drupal has a large community of developers and users who contribute to its development and provide support.

• Some popular websites built with Drupal include The Economist, NBC, and the White House.

A program to reverse a string

• Iterate through the string from end to start and append each character to a new string

• Use built-in functions like reverse() or StringBuilder.reverse() in some programming languages

• Convert the string to an array, reverse the array, and then convert it back to a string

Polymorphism is the ability of an object to take on many forms. Inheritance is the process of creating new classes from existing ones.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• Inheritance allows a class to inherit properties and methods from another class.

• Polymorphism and inheritance are key concepts in object-oriented programming (OOP).

• Example of polymorphism: A superclass Animal with subclasses Dog, Cat, and Bird. They ...read more

Joining a new team requires understanding the team dynamics and culture.

• Take time to observe and learn about the team's communication style and work processes.

• Be open to feedback and willing to adapt to the team's way of doing things.

• Build relationships with team members and establish trust through open communication.

• Ask questions and seek clarification to ensure a clear understanding of expectations and goals.

• Contribute your skills and expertise to the team while also being ...read more

CI/CD pipeline is a set of automated processes for building, testing, and deploying software. String manipulation programs involve manipulating text data.

• CI/CD pipeline automates the process of integrating code changes, testing them, and deploying them to production.

• String manipulation programs involve tasks like searching, replacing, and modifying text data.

• Examples of string manipulation programs include finding the length of a string, converting text to uppercase, and extr...read more

Async coding styles involve writing code that allows for non-blocking operations and efficient use of resources.

• Callbacks: Passing functions as arguments to be executed once an asynchronous operation is completed.

• Promises: Representing a value that may be available in the future, allowing chaining of operations.

• Async/Await: Syntactic sugar for writing asynchronous code in a synchronous style.

• Event Emitters: Using events to signal completion of asynchronous operations.

Program to find duplicates in a list

• Create an empty list to store duplicates

• Loop through the list and check if the element appears more than once

• If yes, add it to the duplicates list

• Return the duplicates list

Optimization techniques for React include code splitting, lazy loading, memoization, and virtualization.

• Code splitting: Break down the code into smaller chunks to load only what is necessary for each page.

• Lazy loading: Load components only when they are needed, improving initial load time.

• Memoization: Cache the results of expensive function calls to avoid redundant calculations.

• Virtualization: Render only the visible elements in a list, improving performance for large dataset...read more

An interface is a contract between two components that defines the communication between them.

• Interfaces provide a way to achieve abstraction and loose coupling in software design.

• They allow different components to communicate with each other without knowing the implementation details.

• Interfaces are used in object-oriented programming to define a set of methods that a class must implement.

• Examples of interfaces in Java include Serializable, Comparable, and Runnable.

• Interfaces...read more

Databricks is built on Apache Spark, a unified analytics engine for big data processing.

• Databricks is built on top of Apache Spark, which provides a unified analytics engine for big data processing.

• It offers a collaborative platform for data scientists, data engineers, and business analysts to work together.

• Databricks provides tools for data ingestion, data processing, machine learning, and visualization.

• It supports multiple programming languages like Python, Scala, SQL, and ...read more

PUT is used to update an existing resource while POST is used to create a new resource.

• PUT is idempotent, meaning multiple identical requests will have the same effect as a single request.

• POST is not idempotent and can result in multiple resources being created if the request is sent multiple times.

• PUT requires the client to send the entire updated resource while POST only requires the necessary fields to create a new resource.

• PUT is typically used for updating data while POS...read more

Control flow of automation framework refers to the sequence in which the test cases are executed.

• The framework follows a predefined sequence of steps to execute test cases

• It includes steps like test case selection, test data preparation, test case execution, and result reporting

• The control flow can be linear or non-linear depending on the framework design

• Example: In a linear control flow, test cases are executed one after the other in a predefined order

Backend development focuses on server-side logic and databases, while front end development focuses on user interface and client-side functionality.

• Backend development involves writing server-side code using languages like Java, Python, or Node.js.

• Front end development involves creating user interfaces using HTML, CSS, and JavaScript.

• Backend developers work on databases, APIs, and server-side logic.

• Front end developers focus on creating visually appealing and interactive user...read more

NodeJs achieves multiple threading through event loop and asynchronous non-blocking I/O operations.

• NodeJs uses event loop to handle multiple requests efficiently without blocking the main thread.

• It utilizes asynchronous non-blocking I/O operations to perform tasks concurrently.

• NodeJs can also create child processes to handle heavy computational tasks in parallel.

A program to write odd and even numbers using a third variable.

• Declare three variables: num, even, and odd.

• Take input from the user for num.

• Use if-else statement to check if num is even or odd.

• If even, assign num to even variable, else assign to odd variable.

• Print even and odd variables.

Yes, we can call queueable class from batch class.

• Batch class can call a queueable class to perform additional processing after the batch job completes.

• Queueable class can be called from the finish method of the batch class.

• This allows for asynchronous processing of data.

• Example: Batch class processes records and calls a queueable class to send email notifications.

OOPs stands for Object-Oriented Programming, JRuby is a Ruby implementation on the Java Virtual Machine, and GitHub commands are used for version control.

• OOPs 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.

• JRuby is a Ruby implementation that runs on the Java Virtual Machine, allowing Ruby code to interact with Java libraries.

• GitHub commands are used to interact with repositories on the...read more

The recent project flow involved data extraction, transformation, and loading using ETL tools.

• The project started with identifying the data sources and requirements.

• Then, the data was extracted from various sources using ETL tools like Informatica, Talend, etc.

• The extracted data was transformed as per the business rules and requirements.

• Finally, the transformed data was loaded into the target system.

• The project also involved testing the ETL process and ensuring data accuracy ...read more

Data security refers to the protection of digital data from unauthorized access, use, disclosure, disruption, modification, or destruction.

• Ensuring data confidentiality by encrypting sensitive information

• Implementing access controls to restrict unauthorized users from accessing data

• Regularly updating security measures to protect against evolving threats

• Backing up data to prevent loss in case of a security breach

Parameters considered while designing a system

• Functional requirements

• Performance requirements

• Scalability

• Security

• Maintainability

• Cost

• User experience

• Integration with existing systems

Dynamic web tables can be handled using various methods like XPath, CSS selectors, and Selenium commands.

• Identify the table element using its HTML tag and attributes

• Use Selenium commands like findElement() and findElements() to locate the table and its rows/columns

• Iterate through the rows and columns using loops and extract the required data

• Use XPath or CSS selectors to locate specific cells or data within the table

• Handle pagination if the table has multiple pages

• Verify the a...read more

Node.js scaling involves horizontal scaling and load balancing. Event loop is a single-threaded, non-blocking I/O model.

• Node.js scaling involves horizontal scaling and load balancing

• Event loop is a single-threaded, non-blocking I/O model

• Horizontal scaling involves adding more servers to handle increased traffic

• Load balancing distributes incoming requests across multiple servers

• Event loop allows Node.js to handle multiple concurrent requests efficiently

• Event loop uses an event...read more

Python uses automatic memory management through garbage collection.

• Python uses reference counting to keep track of objects in memory.

• When an object's reference count reaches zero, it is deleted by the garbage collector.

• Python also uses a cyclic garbage collector to detect and delete objects with circular references.

• Memory can be managed manually using the ctypes module.

• Python's memory management is efficient and transparent to the developer.

Code for database connectivity

• Import the required database driver

• Create a connection object using the driver

• Establish connection to the database using connection object

• Execute SQL queries using the connection object

• Close the connection

Java 8 introduced several new features such as lambda expressions, streams, and functional interfaces.

• Lambda expressions allow for more concise code by enabling functional programming.

• Streams provide a way to work with collections in a more functional style, allowing for parallel processing and lazy evaluation.

• Functional interfaces are interfaces with a single abstract method, which can be implemented using lambda expressions.

• Other features include default methods in interfac...read more

A palindrome is a word, phrase, number, or other sequence of characters that reads the same forward and backward.

• Check if the string is equal to its reverse to determine if it is a palindrome.

• Ignore spaces and punctuation when checking for palindromes.

• Examples: 'racecar', 'madam', '12321'

Check if a string is a palindrome in Python

• Use string slicing to reverse the string and compare with the original string

• Remove spaces and convert to lowercase for accurate comparison

• Use a for loop to iterate through the string and check if it is a palindrome

SOLID principles are a set of five design principles for writing maintainable and scalable code.

• S - Single Responsibility Principle: A class should have only one reason to change.

• O - Open/Closed Principle: Software entities should be open for extension but closed for modification.

• L - Liskov Substitution Principle: Subtypes should be substitutable for their base types.

• I - Interface Segregation Principle: Clients should not be forced to depend on interfaces they do not use.

• D - ...read more

Use a HashSet to find duplicate elements in an array of strings.

• Create a HashSet to store unique elements.

• Iterate through the array and check if the element is already in the HashSet.

• If it is, then it is a duplicate element.

• Example: String[] array = {"apple", "banana", "apple", "orange"};