20+ Marc Laboratories Interview Questions and Answers

The question asks to implement a data structure called 'MapSum' with functions to initialize, insert key-value pairs, and find the sum of values with a given prefix.

• Implement a class called 'MapSum' with a constructor to initialize the data structure.

• Implement the 'insert' function to insert key-value pairs into the 'MapSum'. If a key is already present, replace its value with the new one.

• Implement the 'sum' function to find the sum of values whose key has a prefix equal to t...read more

The task is to reverse a given string containing alphanumeric and special characters.

• Iterate through the string from the last character to the first character

• Append each character to a new string to get the reversed string

• Return the reversed string as the output

Comparator is used to compare objects of different classes while Comparable is used to compare objects of the same class.

• Comparator is an interface that needs to be implemented to compare objects of different classes.

• Comparable is an interface that needs to be implemented to compare objects of the same class.

• Comparator uses compare() method while Comparable uses compareTo() method.

• Comparator can be used to sort a collection in any order while Comparable can only sort in natur...read more

Code migration involves understanding the existing codebase, planning the migration process, translating code to the new language, testing thoroughly, and ensuring compatibility.

• Understand the existing codebase thoroughly to identify dependencies, logic, and functionality.

• Plan the migration process by breaking it down into smaller tasks, setting timelines, and allocating resources.

• Translate the code to the new language by rewriting or using automated tools like transpilers.

• Te...read more

Pointers in C are used to store memory addresses, storage classes determine the scope and lifetime of variables, memory layout refers to how data is organized in memory, endianness refers to byte order, COM stack is a communication protocol.

• Pointers in C are used to store memory addresses of variables.

• Storage classes in C determine the scope and lifetime of variables.

• Memory layout in C refers to how data is organized in memory.

• Endianness in C refers to the byte order of multi...read more

Program to print duplicate characters in a string

• Create a map to store characters and their counts

• Iterate through the string and update the map

• Print characters with count > 1 as duplicates

Fall fast refers to failing quickly and early in the development process, while fall safe refers to implementing safety measures to prevent failures.

• Fall fast involves identifying and addressing issues early on in the development cycle.

• Fall safe involves implementing safety measures such as error handling and redundancy to prevent failures.

• An example of fall fast is using automated testing to catch bugs early in the development process.

• An example of fall safe is implementing ...read more

Activity call backs are used to handle configuration changes in software.

• Activity call backs are methods that are called when certain events occur in an activity's lifecycle.

• They are commonly used to handle configuration changes such as screen rotation or language changes.

• By implementing activity call backs, developers can save and restore important data or update the UI accordingly.

• Examples of activity call backs include onCreate(), onPause(), onResume(), etc.

Java is a popular programming language known for its portability and OOPS is a programming paradigm based on objects and classes.

• Java is a high-level, class-based, object-oriented programming language.

• OOPS (Object-Oriented Programming) 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 concepts include Inheritance, Encapsulation, Polymorphism, and Abstraction.

• Example: In Java, you can...read more

Await and Sync are programming concepts used for managing asynchronous operations in code execution.

• Await is used to pause the execution of a function until a Promise is settled, returning the result.

• Sync is used to synchronize multiple threads or processes to ensure they are executed in a specific order.

• Example: await fetch('https://api.example.com/data')

• Example: sync.Mutex.Lock()

• Both Await and Sync are important for handling concurrency and improving performance in software...read more

Program to check if a string is a palindrome or not

• Create a function that takes a string as input

• Remove all non-alphanumeric characters and convert to lowercase

• Compare the original string with its reverse to check if it's a palindrome

• Return true if it's a palindrome, false otherwise

Spring Boot is a framework that simplifies the development of Java applications.

• Provides a pre-configured environment for building production-grade applications

• Reduces boilerplate code and configuration

• Supports a wide range of data sources and integrations

• Enables easy deployment and scaling of applications

• Offers built-in security features

• Example: Spring Boot can be used to quickly create a RESTful API with minimal setup

Observables are a way to handle asynchronous data streams in Angular.

• Observables are similar to Promises but can handle multiple values over time.

• They can be created using the RxJS library.

• They can be used for handling HTTP requests, user input, and other asynchronous events.

• Operators can be used to transform, filter, and combine observables.

• Subscriptions are used to listen for and handle emitted values from observables.

The init block in Kotlin is used to initialize properties or execute code when an object is created.

• The init block is defined inside a class and is executed immediately after the primary constructor.

• It can be used to initialize properties or perform any other necessary setup.

• Multiple init blocks can be defined in a class, and they are executed in the order of their appearance.

• The init block is useful when you need to execute code during object creation that cannot be handled ...read more

RxJS is a reactive programming library for JavaScript.

• RxJS allows for easier management of asynchronous data streams.

• It provides operators for filtering, transforming, and combining data streams.

• RxJS can be used in both front-end and back-end development.

• Examples of its use include handling user input, making HTTP requests, and managing state in a Redux store.

Microservices are developed by breaking down a large application into smaller, independent services that communicate with each other through APIs.

• Identify the boundaries of each microservice based on business capabilities

• Design each microservice to be independent and loosely coupled

• Use lightweight protocols like HTTP or messaging queues for communication between microservices

• Implement each microservice using the technology stack best suited for its requirements

• Deploy microser...read more

Selenium WebDriver is a tool used for automating web application testing.

• Selenium WebDriver is a popular automation tool for testing web applications.

• It supports multiple programming languages such as Java, Python, C#, etc.

• WebDriver interacts with the web browser to simulate user actions like clicking buttons, entering text, etc.

• It can run tests on different browsers like Chrome, Firefox, Safari, etc.

• WebDriver can handle complex scenarios like handling pop-ups, alerts, frames...read more

OOPS concepts refer to Object-Oriented Programming principles such as 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.

Agile methodology is a project management approach that emphasizes flexibility, collaboration, and incremental development.

• Agile focuses on delivering working software in short, iterative cycles called sprints.

• It values customer collaboration, responding to change, and continuous improvement.

• Key principles include individuals and interactions over processes and tools, working software over comprehensive documentation, customer collaboration over contract negotiation, and resp...read more

CAN protocol is a communication protocol used in automotive and industrial applications for high-speed data transmission.

• CAN stands for Controller Area Network

• It is a message-based protocol used for communication between electronic control units (ECUs) in vehicles

• CAN uses a two-wire bus for communication - CAN High and CAN Low

• Messages in CAN protocol are prioritized based on their identifier

• CAN supports two message formats - Standard CAN and Extended CAN

• Error detection and fa...read more

React Router DOM is a popular routing library for React applications.

• Used for handling routing in React applications

• Allows for declarative routing using components like BrowserRouter, Route, Switch, etc.

• Enables navigation between different components without full page reloads

Program to check if a given string is a palindrome

• Create a function that takes a string as input

• Remove all non-alphanumeric characters and convert to lowercase

• Compare the string with its reverse to check if it is a palindrome

Oops concepts are fundamental principles of object-oriented programming such as inheritance, polymorphism, encapsulation, and abstraction.

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

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

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

• Abstraction: Hiding the implementation details and showing onl...read more

MEAN stack app development involves using MongoDB, Express.js, Angular, and Node.js

• Use MongoDB as the database to store data

• Utilize Express.js for building the backend API

• Develop the frontend using Angular framework

• Use Node.js for server-side scripting and handling requests