20+ Marken Interview Questions and Answers

Abstract class can have implementation while interface cannot. A class can implement multiple interfaces but only extend one abstract class.

• Abstract class can have constructors while interface cannot.

• Abstract class can have non-abstract methods while interface can only have abstract methods.

• A class can implement multiple interfaces but only extend one abstract class.

• Abstract class can have instance variables while interface cannot.

• Abstract class is used for code reusability w...read more

Primary key uniquely identifies a record in a table, while unique key ensures that all values in a column are distinct.

• Primary key is used to enforce entity integrity, while unique key enforces domain integrity.

• A table can have only one primary key, but multiple unique keys.

• Primary key can't have null values, while unique key can have null values.

• Primary key is automatically indexed, while unique key may or may not be indexed.

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

• Arrow functions have a shorter syntax compared to regular functions.

• They do not have their own 'this' value, instead, they inherit 'this' from the surrounding context.

• Arrow functions are always anonymous and cannot be used as constructors.

• They are commonly used in React components for event handlers and callback functions.

Interfaces in Java provide a way to achieve abstraction and multiple inheritance.

• Interfaces define a set of methods that a class must implement.

• They allow for loose coupling between classes.

• Interfaces can be used to achieve polymorphism.

• Java does not support multiple inheritance, but interfaces provide a way to achieve it.

• Interfaces are used extensively in Java frameworks like Spring and Hibernate.

To join three different tables in SQL, you can use the JOIN keyword along with the appropriate join conditions.

• Use the JOIN keyword to combine tables based on a common column

• Specify the join conditions using the ON keyword

• You can join more than two tables by chaining multiple JOIN statements

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

Overloading is having multiple methods with the same name but different parameters. Overriding is implementing a method in a subclass that already exists in the parent class.

• Overloading is compile-time polymorphism while overriding is runtime polymorphism.

• Overloading is used to provide different ways of calling the same method with different parameters.

• Overriding is used to provide a specific implementation of a method in a subclass that is already defined in the parent class...read more

Yes, exception handling is required in a big project.

• Exception handling helps in identifying and resolving errors during runtime.

• It improves the stability and reliability of the application.

• Exceptions can occur due to various reasons like network issues, server errors, or user input errors.

• Handling exceptions gracefully prevents the application from crashing and provides a better user experience.

• It allows for proper error logging and debugging, making it easier to identify an...read more

Access specifiers in Java are keywords that determine the visibility of a class, method, or variable.

• There are four access specifiers in Java: public, private, protected, and default.

• Public: accessible from anywhere in the program.

• Private: accessible only within the same class.

• Protected: accessible within the same class, subclasses, and same package.

• Default: accessible within the same package only.

Encapsulation is a mechanism of wrapping data and code acting on the data together as a single unit.

• Encapsulation is used to hide the implementation details of an object from the outside world.

• It helps in achieving data abstraction and data hiding.

• In Java, encapsulation is achieved by declaring the variables of a class as private and providing public getter and setter methods to access and modify the data.

• Example: A bank account class with private variables like account numbe...read more

SQL Server Agent is a job scheduling tool in SQL Server. Abstract classes cannot be instantiated. SPs are faster than functions. Microservice concepts. IEnumerable vs IQueryable.

• SQL Server Agent is a job scheduling tool in SQL Server for automating tasks like backups, database maintenance, etc.

• Abstract classes cannot be instantiated because they are incomplete and meant to be extended by subclasses.

• Extension methods can be created for abstract classes to add new functionality...read more

Answers to various technical questions related to React Native development.

• 1. Git rebase is used to reapply commits on top of another base tip. It is used to maintain a clean and linear project history.

• 2. Flipper is a mobile debugging tool for iOS and Android apps. It allows developers to inspect and debug their apps in real-time.

• 3. useCallback is a hook in React that returns a memoized callback function. It is used to optimize performance by preventing unnecessary re-renders...read more

A record in C# is a data structure that stores a fixed number of fields of different data types.

• A record in C# is similar to a struct in C++, containing fields to store data.

• Example: 'public record Person { public string Name; public int Age; }'

• Generic method for summation: 'public T Sum(T a, T b) where T : struct, IConvertible { return Convert.ToDouble(a) + Convert.ToDouble(b); }'

• Test cases can include checking the sum of integers, doubles, floats, etc.

• Design pattern used ca...read more

Handling conflicts with team members requires open communication, active listening, empathy, and a focus on finding a mutually beneficial solution.

• Address the conflict directly and in a timely manner

• Listen actively to the other person's perspective

• Express your own thoughts and feelings calmly and respectfully

• Seek to understand the root cause of the conflict

• Collaborate on finding a solution that works for both parties

• Maintain professionalism and focus on the team's goals

Targeting involves identifying a specific group of candidates, while headhunting is actively seeking out and approaching top talent.

• Targeting focuses on a specific group of candidates based on criteria such as skills, experience, or industry.

• Headhunting involves actively seeking out and approaching top talent, often individuals who are not actively looking for a job.

• Targeting is more passive and relies on attracting candidates through job postings or networking events.

• Headhun...read more

Cold leads are potential customers who have shown little to no interest in the product or service, while hot leads are highly interested and likely to make a purchase. Cold emails are unsolicited emails sent to potential customers who have not expressed interest.

• Cold leads have not shown interest in the product or service

• Hot leads are highly interested and likely to make a purchase

• Cold emails are unsolicited emails sent to potential customers

• Cold emails are often used to gene...read more

The IT sector is important because it drives innovation, efficiency, and productivity in businesses.

• IT sector enables businesses to streamline operations and improve communication through technology.

• It fosters innovation by constantly developing new solutions and products.

• Tech Sales involves selling technology products and services to businesses or consumers.

• Sales is important in driving revenue and growth for companies.

• It helps in building relationships with customers and un...read more

Backend and Frontend technologies refer to the technologies used to develop the server-side and client-side of a web application, respectively.

• Backend technologies include languages like Java, Python, Ruby, and frameworks like Node.js, Django, Flask

• Frontend technologies include HTML, CSS, JavaScript, and frameworks like React, Angular, Vue.js

• Backend technologies handle server-side logic, database interactions, and API integrations

• Frontend technologies focus on user interface,...read more

I use the latest stable version of React for my projects.

• I always make sure to update to the latest stable version to take advantage of new features and improvements.

• For example, I am currently using React version 17.0.2 in my projects.

• I also keep an eye on the React release notes to stay informed about any breaking changes or deprecations.

Reconciliation in ReactJs is the process of updating the DOM to match the virtual DOM after a state change.

• Reconciliation is the algorithm that React uses to update the UI efficiently.

• It compares the virtual DOM with the previous virtual DOM and only updates the necessary components.

• Reconciliation is a key feature that helps React achieve high performance.

• Example: When a user clicks a button causing a state change, React uses reconciliation to update only the changed componen...read more

LinkedIn is a social networking platform for professionals, while Recruiter is a tool within LinkedIn for recruiters to find and connect with potential candidates.

• LinkedIn is a platform for professionals to network and showcase their skills and experience.

• Recruiter is a tool within LinkedIn that allows recruiters to search for and connect with potential candidates for job opportunities.

• LinkedIn is used by individuals to build their professional brand and connect with others i...read more

Lambda limitations include execution time limits, memory limits, and cold start delays.

• Lambda functions have a maximum execution time limit of 15 minutes.

• Lambda functions have memory limits ranging from 128 MB to 3 GB.

• Lambda functions may experience cold start delays due to initialization of resources.

My expected CTC is based on my experience, skills, and the market rate for Reactjs Developers.

• My expected CTC is in line with industry standards for Reactjs Developers.

• I have considered my level of experience and expertise in Reactjs development.

• I am open to negotiation based on the overall compensation package offered by the company.

Virtual DOM is a lightweight copy of the actual DOM that React uses to efficiently update the UI.

• Virtual DOM is a representation of the actual DOM in memory.

• When state changes, React compares the Virtual DOM with the actual DOM to identify the differences.

• React then updates only the necessary parts of the actual DOM, minimizing performance impact.

Types of testing include unit testing, integration testing, system testing, acceptance testing, and regression testing.

• Unit testing: Testing individual components or modules of a software application.

• Integration testing: Testing the interaction between different components or modules.

• System testing: Testing the entire system as a whole.

• Acceptance testing: Testing to ensure the system meets the requirements of the end users.

• Regression testing: Testing to ensure that new code c...read more

Sales focuses on selling products or services, while marketing focuses on promoting and creating demand for those products or services.

• Sales involves direct interaction with customers to close deals

• Marketing involves creating strategies to attract and retain customers

• Sales is more short-term focused on closing deals, while marketing is more long-term focused on building brand awareness

• Sales is about meeting individual customer needs, while marketing is about understanding and...read more

QA stands for Quality Assurance. It is a process of ensuring that the software or product meets the required quality standards.

• QA involves testing the software or product to identify defects or bugs

• It also involves ensuring that the software or product meets the functional and non-functional requirements

• QA is an ongoing process that starts from the beginning of the software development life cycle and continues until the product is released

• QA also involves creating test plans,...read more

CI/CD stands for Continuous Integration/Continuous Deployment. It is a software development practice where code changes are automatically built, tested, and deployed.

• CI/CD helps automate the process of integrating code changes into a shared repository and deploying them to production.

• Continuous Integration involves automatically building and testing code changes as soon as they are committed to the repository.

• Continuous Deployment involves automatically deploying code changes...read more