200+ Developer Interview Questions and Answers

OOPs stands for Object-Oriented Programming. Inheritance is a feature of OOPs where a class can inherit properties and behaviors from another class.

• OOPs is a programming paradigm that uses objects to design applications.

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

• It promotes code reusability and helps in creating a hierarchical structure of classes.

• Example: Class 'Car' can inherit properties like 'color' and methods like 'drive' from class ...read more

Qlik is a data visualization and business intelligence platform, similar to Power BI.

• Qlik and Power BI are both data visualization and business intelligence tools.

• Qlik offers a unique associative data model that allows users to explore data relationships more easily.

• Power BI has a strong integration with Microsoft products and services.

• Qlik has a more flexible and customizable user interface compared to Power BI.

• Both tools have their own strengths and weaknesses, and the choi...read more

Var is statically typed while dynamic is dynamically typed.

• Var is used to declare variables with a specific type at compile time.

• Dynamic is used to declare variables whose type is determined at runtime.

• Var is faster than dynamic because it doesn't require type checking at runtime.

• Dynamic is more flexible than var because it allows for late binding and duck typing.

• Example: var x = 5; dynamic y = "hello";

Joins are used to combine data from two or more tables based on a related column.

• Types of joins include inner join, left join, right join, and full outer join.

• Inner join returns only the matching rows from both tables.

• Left join returns all the rows from the left table and matching rows from the right table.

• Right join returns all the rows from the right table and matching rows from the left table.

• Full outer join returns all the rows from both tables, with NULL values in the co...read more

Default port numbers for TCP/HTTP/HTTPS

• TCP: 80

• HTTP: 80

• HTTPS: 443

Inheritance is a mechanism in object-oriented programming where a new class is derived from an existing class.

• It allows the new class to inherit the properties and methods of the existing class

• The existing class is called the parent class or superclass, and the new class is called the child class or subclass

• The child class can add new properties and methods or override the existing ones

• Example: A class Animal can be the parent class, and classes like Dog, Cat, and Bird can be...read more

Sorting through a list involves comparing elements and arranging them in a specific order.

• Use a sorting algorithm such as bubble sort, selection sort, or merge sort.

• Consider the data type of the elements in the list to determine the appropriate sorting method.

• Implement the sorting algorithm in your preferred programming language to rearrange the elements in the list.

Encapsulation, Inheritance, Polymorphism, Abstraction

• Encapsulation: bundling of data and methods that act on that data within a single unit

• Inheritance: ability of a class to inherit properties and methods from a parent class

• Polymorphism: ability of objects to take on many forms

• Abstraction: hiding of complex implementation details and showing only the necessary information

OOPS concepts are fundamental principles in object-oriented programming.

• 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: hiding unnecessary details and exposing only essential features

• Encapsulation example: a class with private variables and public methods

• Inheritance example: a subclass inheriting properties and methods from a supercla...read more

Shallow copy creates a new reference to the original object, while deep copy creates a new object with its own copy of the data.

• Shallow copy only copies the references of the original object's data, not the actual data itself.

• Deep copy creates a new object and recursively copies all the data from the original object.

• Shallow copy is faster and more memory-efficient, but changes to the copied data will affect the original object.

• Deep copy is slower and consumes more memory, but...read more

Inheritance in Java allows a class to inherit properties and behaviors from another class.

• Inheritance enables code reusability and promotes a hierarchical relationship between classes.

• Subclasses can access the methods and fields of their superclass.

• Example: class Dog extends Animal, where Dog inherits properties and behaviors from Animal.

JDBC (Java Database Connectivity) is an API that allows Java programs to interact with databases.

• JDBC provides a set of classes and interfaces to connect to and interact with databases.

• It allows developers to write SQL queries, execute them, and process the results.

• JDBC drivers enable communication between Java applications and different types of databases.

• Example: Class.forName("com.mysql.jdbc.Driver"); Connection con = DriverManager.getConnection("jdbc:mysql://localhost:330...read more

Boto3 is used for AWS SDK and Moto is used for testing AWS services locally.

• Boto3 is a Python library used for interacting with AWS services.

• Moto is a Python library used for testing AWS services locally.

• Moto allows developers to test their code without incurring AWS costs.

• Boto3 and Moto are often used together for testing AWS services locally.

Event loop in React is responsible for handling asynchronous operations and updating the UI.

• Event loop is a mechanism that allows JavaScript to perform non-blocking operations.

• In React, the event loop is used to handle tasks like updating the UI, handling user interactions, and fetching data from APIs.

• Event loop ensures that the application remains responsive by prioritizing certain tasks over others.

• Example: When a user clicks a button in a React application, the event loop ...read more

My technical skills include proficiency in programming languages such as Java, Python, and JavaScript, as well as experience with databases and web development.

• Proficient in Java, Python, and JavaScript

• Experience with databases such as MySQL and MongoDB

• Knowledge of web development technologies like HTML, CSS, and React

• Familiarity with version control systems like Git

LIFO can be better for inventory management and tax purposes.

• LIFO assumes that the last items purchased are the first ones sold, which can result in lower taxes during inflation.

• LIFO can also help reduce the risk of obsolescence by selling newer inventory first.

• LIFO can be easier to manage and track compared to FIFO or average cost methods.

• LIFO is commonly used in industries with rapidly changing prices, such as technology or fashion.

• However, LIFO can also result in higher co...read more

HashMap is a data structure that stores key-value pairs and provides constant time complexity for basic operations.

• Hashmap uses hashing to store and retrieve values based on keys.

• It uses an array of buckets to store key-value pairs.

• The hash function maps the key to an index in the array.

• If multiple keys map to the same index, a linked list is used to store them.

• Basic operations like put, get, and remove have constant time complexity on average.

• Java's HashMap implementation al...read more

ASP.NET life cycle is the series of events that occur during the processing of a request.

• ASP.NET life cycle includes stages like initialization, page rendering, and disposal.

• During initialization, the page and its controls are created and initialized.

• During page rendering, the page is processed and HTML is generated.

• During disposal, resources used by the page are released.

• Events like Page_Load and Page_PreRender occur during the life cycle.

• Understanding the life cycle is impo...read more

View state is a hidden state of the page that stores values of controls and other page-specific data.

• View state is used to maintain the state of server-side controls between postbacks.

• It is stored in a hidden field on the page and is encrypted for security purposes.

• View state can be disabled to improve performance, but this may cause issues with control state.

• Example: A user fills out a form, but then navigates away from the page. When they return, their form data is still th...read more

A unique key is a field or combination of fields in a database table that uniquely identifies each record.

• A unique key ensures that no two records in a table have the same values for the specified field(s).

• It can be a single field or a combination of fields.

• It is used to enforce data integrity and prevent duplicate records.

• Examples include primary keys, candidate keys, and alternate keys.

I am proficient in various technologies including Java, Python, HTML/CSS, JavaScript, and SQL.

• Proficient in Java and Python programming languages

• Familiar with HTML/CSS and JavaScript for web development

• Experience with SQL for database management

• Knowledge of Git for version control

• Familiarity with Agile methodology for software development

• Experience with AWS for cloud computing

• Experience with Docker for containerization

A constraint is a limitation or restriction on something.

• Constraints can be applied in various fields such as software development, engineering, and project management.

• In software development, constraints can include limitations on memory usage, processing speed, and storage capacity.

• In engineering, constraints can include limitations on materials, dimensions, and weight.

• In project management, constraints can include limitations on time, budget, and resources.

• Examples of cons...read more

Joins in SQL 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

Triggers are database objects that are automatically executed or fired when certain events occur in a database.

• Triggers are used to maintain referential integrity, enforce business rules, and automate tasks.

• They can be classified as DML triggers (executed in response to data manipulation language events) or DDL triggers (executed in response to data definition language events).

• For example, a trigger can be created to automatically update a 'last_modified' column in a table wh...read more

The work environment is collaborative and supportive.

• The team is friendly and helpful

• Open communication is encouraged

• Flexible work hours and remote work options are available

Print prime numbers between 1 to 10

• A prime number is a number that is only divisible by 1 and itself

• The prime numbers between 1 to 10 are: 2, 3, 5, 7

CDC stage refers to the different stages of the Centers for Disease Control and Prevention's response to a public health emergency.

• CDC Stage 1: Recognize the threat and assess the situation.

• CDC Stage 2: Develop a plan and mobilize resources.

• CDC Stage 3: Implement the plan and monitor the situation.

• CDC Stage 4: Evaluate the response and adjust as needed.

• CDC Stage 5: Transition back to normal operations.

• Example: During the COVID-19 pandemic, CDC moved through different stages t...read more

C and C++ are programming languages used for system and application development.

• C is a procedural language used for system programming and embedded systems.

• C++ is an object-oriented language used for application development and game programming.

• Both languages are compiled and have a strong influence on modern programming languages.

• C++ is an extension of C with additional features like classes, templates, and exceptions.

• Examples of C and C++ applications include operating syst...read more

Qualification refers to the skills, knowledge, and experience required for a particular job or profession.

• Qualification is a set of requirements that an individual must meet to be considered for a job or profession.

• It can include educational degrees, certifications, licenses, and relevant work experience.

• Qualifications vary depending on the job or profession, and may be mandatory or preferred.

• For example, a software developer may require a degree in computer science and exper...read more

SAP DataSphere is a data management platform that enables organizations to collect, analyze, and visualize data from various sources.

• SAP DataSphere helps organizations to centralize and integrate data from multiple systems and sources.

• It provides tools for data cleansing, transformation, and enrichment.

• The platform offers advanced analytics capabilities to gain insights from the collected data.

• SAP DataSphere supports data visualization and reporting to facilitate data-driven ...read more

useEffect is a hook in React that allows you to perform side effects in function components.

• useEffect is used to perform side effects in function components, such as data fetching, subscriptions, or manually changing the DOM.

• It runs after every render by default, but you can also specify dependencies to control when it runs.

• Example: useEffect(() => { console.log('Component rendered'); }, []);

Developed a social media campaign for a new product launch

• Created a hashtag for the campaign

• Collaborated with influencers to promote the product

• Designed eye-catching graphics for social media posts

Count distinct characters in a string

• Iterate through each character in the string

• Use a hash set to keep track of distinct characters

• Return the size of the hash set as the count of distinct characters

The cond parameter is a conditional parameter used in programming to evaluate a series of conditions and return a value based on the first condition that is true.

• Cond parameter is commonly used in programming languages like Lisp and Clojure.

• It takes a series of pairs where the first element is a condition and the second element is the value to return if the condition is true.

• Example: (cond ((= x 0) 'zero) ((= x 1) 'one) (true 'other))

Exception handling is the process of responding to unexpected events or errors in a program.

• Exception handling allows developers to gracefully handle errors and prevent crashes in a program.

• It involves using try, catch, and finally blocks to handle exceptions.

• Examples include catching a divide by zero error or a file not found exception.

Nodejs is a runtime environment for executing JavaScript code outside of a web browser.

• Nodejs is built on top of the V8 JavaScript engine

• JavaScript is a programming language used for both front-end and back-end development

• Nodejs allows for server-side scripting and can be used to build scalable network applications

• JavaScript is primarily used for client-side scripting in web browsers

Azure Databricks is a unified analytics platform that combines big data processing and machine learning.

• Collaborative environment for data scientists, data engineers, and business analysts

• Integrated with Azure services for data storage, processing, and analytics

• Supports popular programming languages like Python, Scala, and SQL

• Provides tools for data visualization and machine learning model development

Cache in Databricks is a mechanism to store intermediate results of computations for faster access.

• Cache in Databricks is used to store intermediate results of computations in memory for faster access.

• It helps in reducing the time taken to recompute the same data by storing it in memory.

• Data can be cached at different levels such as DataFrame, RDD, or table.

• Example: df.cache() will cache the DataFrame 'df' in memory for faster access.

Polymorphism is the ability of an object to take on many forms.

• Polymorphism allows objects of different classes to be treated as if they were objects of the same class.

• It is achieved through method overriding and method overloading.

• Example: A parent class Animal can have child classes like Dog, Cat, and Bird. Each child class can have its own implementation of the method 'makeSound'.

• Polymorphism makes code more flexible and reusable.

LPA can refer to several things depending on the context.

• LPA can stand for Licensed Professional Accountant.

• LPA can also refer to Lysophosphatidic acid, a signaling molecule involved in various physiological processes.

• In the legal field, LPA can stand for Lasting Power of Attorney, a legal document that allows someone to make decisions on behalf of another person.

• LPA can also refer to the Lateral Plate Mesoderm, a layer of cells in the developing embryo that gives rise to var...read more

CPP is better due to its performance, memory management, and object-oriented features.

• CPP is faster than many other programming languages due to its compiled nature.

• CPP allows for manual memory management, which can lead to more efficient use of resources.

• CPP supports object-oriented programming, which can make code more modular and easier to maintain.

• CPP has a large community and many libraries available, making it a versatile language for various applications.

SDLC is a process used by developers to plan, create, test, and deploy software.

• SDLC stands for Software Development Life Cycle

• It includes phases like planning, analysis, design, implementation, testing, and maintenance

• Python is a popular programming language used in the implementation phase of SDLC

Frameworks are pre-written code libraries that provide a foundation for developing software applications.

• Frameworks help developers by providing reusable code and tools for common tasks

• Examples include React for front-end web development, Django for back-end web development, and TensorFlow for machine learning

• Frameworks can speed up development time and improve code quality

Spark engine architecture is a distributed computing framework that provides in-memory processing capabilities.

• Spark engine consists of a driver program that coordinates the execution of tasks on worker nodes.

• Worker nodes execute tasks in parallel and store data in memory for faster processing.

• Spark engine uses Resilient Distributed Datasets (RDDs) for fault-tolerant distributed data processing.

• It supports various programming languages like Java, Scala, and Python for writing...read more

I have extensive experience with .NET technologies.

• .NET Framework: Developed web applications using ASP.NET MVC and Web API.

• C#: Proficient in C# programming language for building robust and scalable applications.

• Entity Framework: Utilized Entity Framework for database access and ORM.

• ASP.NET Core: Developed RESTful APIs using ASP.NET Core framework.

• Azure: Deployed applications on Microsoft Azure cloud platform.

• Unit Testing: Familiar with unit testing frameworks like NUnit and ...read more

To find spaces in a string, use the split() method and count the resulting array length minus one.

• Use the split() method with a space as the delimiter

• Count the length of the resulting array minus one

• Example: 'Hello World'.split(' ').length - 1 returns 1

Null indicator is a flag used to indicate whether a value is null or not in database systems.

• Null indicator is used in database systems to handle null values efficiently.

• It is typically a single bit flag associated with a data field.

• A null indicator value of 0 indicates that the corresponding value is not null, while a value of 1 indicates it is null.