100+ Dot Net Fullstack Developer Interview Questions and Answers

The .NET framework supports multiple languages including C#, VB.NET, F#, and C++.

• C# is the most commonly used language for .NET development

• VB.NET is a popular choice for legacy applications

• F# is used for functional programming

• C++ is used for performance-critical applications

• Other languages like IronPython and IronRuby can also be used with .NET

Catching in .NET is a mechanism to handle exceptions that occur during program execution.

• Catching is done using try-catch blocks.

• Types of catching include specific exception catching, general exception catching, and re-throwing exceptions.

• Specific exception catching is done using catch blocks that specify the type of exception to catch.

• General exception catching is done using catch blocks that catch all exceptions.

• Re-throwing exceptions is done using the throw keyword within ...read more

OOPs concepts like inheritance, encapsulation, polymorphism, and abstraction were used in my previous projects for designing modular and reusable code.

• Inheritance: Used to create parent-child relationships between classes. For example, a base class 'Vehicle' with child classes 'Car' and 'Truck'.

• Encapsulation: Used to hide the internal implementation details of a class and only expose necessary methods and properties. For example, private variables and public methods in a 'Use...read more

Calculate the difference between two integers and find how many numbers within that difference are divisible by 3.

• Calculate the absolute difference between the two integers

• Iterate through the range of numbers within the difference and check if each number is divisible by 3

• Keep a count of numbers divisible by 3

Create a higher-order component in React to fetch and share API data between components.

• Define a higher-order component (HOC) that wraps around the target components.

• Use the fetch API to retrieve data inside the HOC, typically in a useEffect hook.

• Store the fetched data in the HOC's state using useState.

• Pass the fetched data as props to the wrapped components.

• Handle loading and error states to improve user experience.

OOPs is a programming paradigm that uses objects to represent real-world entities. .NET framework supports OOPs concepts.

• OOPs stands for Object-Oriented Programming.

• .NET framework supports OOPs concepts like encapsulation, inheritance, and polymorphism.

• In OOPs, objects are created from classes, which act as blueprints for the objects.

• Example: In .NET, a class can be created to represent a customer with properties like name, address, and methods like placeOrder().

• OOPs helps in...read more

JIT stands for Just-In-Time compilation. It is a technique used by programming languages to improve performance.

• JIT compiles code at runtime instead of ahead of time

• It converts bytecode into machine code

• There are two types of JIT: Pre-JIT and Normal JIT

• Pre-JIT compiles the entire codebase ahead of time

• Normal JIT compiles code as it is needed during runtime

Create a simple model view controller to retrieve values from a database

• Create a model class to represent the data structure from the database

• Create a controller to handle requests and interact with the model

• Create a view to display the data retrieved from the database

Use the OFFSET and FETCH clauses in SQL to get the 5th top position data.

• Use the ORDER BY clause to sort the data in descending order.

• Use the OFFSET clause to skip the first 4 rows.

• Use the FETCH clause to retrieve only the next row after skipping the first 4 rows.

Resolvers in Angular are used to fetch data before the component is loaded, canActivate guards control access to routes, custom decorators can be created using @Decorator syntax, ngOnInit is a lifecycle hook in Angular, asynchronous methods can be made synchronous using async/await, cancellation tokens are used to cancel asynchronous operations.

• Resolvers in Angular are used to fetch data before the component is loaded, ensuring that the component has the necessary data when i...read more

Authentication verifies the identity of a user, while authorization determines what resources a user can access.

• Authentication confirms the identity of a user through credentials like username and password.

• Authorization determines the permissions and access levels of a user based on their authenticated identity.

• In ASP.NET Core, authentication is handled through middleware like Identity, OAuth, or JWT tokens.

• Authorization in ASP.NET Core is managed through policies and roles d...read more

Identify first occurrences of vowels in a string and return their indices along with count.

• Loop through the string and check if each character is a vowel (a, e, i, o, u)

• Store the index of the first occurrence of each vowel in a separate array

• Return the array of indices and the count of indices

Use ROW_NUMBER() to rank salaries and retrieve the highest salary from a table.

• ROW_NUMBER() assigns a unique sequential integer to rows within a partition.

• To get the highest salary, order by salary in descending order.

• Example SQL query: SELECT Salary FROM (SELECT Salary, ROW_NUMBER() OVER (ORDER BY Salary DESC) AS rn FROM Employees) AS ranked WHERE rn = 1.

Creating a controller with LINQ to retrieve specific order data involves defining routes, queries, and returning results.

• Define a controller class, e.g., 'OrdersController'.

• Inject the DbContext to access the database.

• Create an action method, e.g., 'GetOrdersByCustomerId'.

• Use LINQ to query the orders, e.g., 'context.Orders.Where(o => o.CustomerId == id)'.

• Return the results as JSON using 'Ok()' or 'NotFound()' for error handling.

Design a login page with OTP verification sent to user's mobile.

• Create a login page with fields for mobile number and OTP input

• Generate and send OTP to user's mobile number upon submission of mobile number

• Verify OTP entered by user before allowing login

• Implement timeout for OTP validity to enhance security

Logic App logs are stored in Azure Monitor Logs (formerly known as Log Analytics).

• Logic App logs are stored in Azure Monitor Logs, which is a centralized log storage and analytics service in Azure.

• Logs can be viewed and analyzed using Azure Monitor Logs queries.

• Logs can also be integrated with other Azure services for monitoring and alerting purposes.

Abstract classes can have implementation; interfaces cannot. Both define contracts for derived classes.

• An abstract class can contain both abstract methods (without implementation) and concrete methods (with implementation).

• An interface can only contain method signatures and properties; it cannot provide any implementation.

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

• Example of an abstract class: 'public abstract class Animal { public ...read more

Out parameter is used to pass data out of a method or function.

• Out parameters are used when a method needs to return multiple values.

• They are declared using the 'out' keyword in C#.

• Example: void CalculateArea(int length, int width, out int area) { area = length * width; }

Denouncing and throttling optimize performance by controlling event handling and reducing unnecessary processing.

• Debouncing: Ensures a function is only called after a specified delay, preventing multiple calls during rapid events. Example: Search input.

• Throttling: Limits the number of times a function can be executed over time, ensuring it runs at regular intervals. Example: Scroll events.

• Use cases: Debouncing is ideal for user input scenarios, while throttling is better for ...read more

Polymorphism is the ability of a single function or method to operate on different data types. Interface is a contract that defines the methods that a class must implement. Multithreading is the ability of a CPU to execute multiple threads concurrently. C# does not support multiple inheritance. Inheritance is a mechanism in OOP where a class inherits properties and behaviors from another class. Methods are functions defined within a class. void main() is the entry point of a ...read more

Static constructor is used to initialize static data members of a class.

• Executed only once when the class is first accessed

• Cannot have any access modifiers or parameters

• Used to initialize static variables or perform any necessary setup tasks

SQL queries for creating database tables using DML and DDL

• Use CREATE TABLE statement for DDL to create a new table

• Use INSERT INTO statement for DML to insert data into the table

• Use SELECT statement to retrieve data from the table

• Use UPDATE statement to modify existing data in the table

• Use DELETE statement to remove data from the table

Session management in ASP.NET Core involves storing and retrieving user-specific data during a user's visit to a website.

• Session data is stored on the server side by default in ASP.NET Core

• Session data can be accessed and manipulated using the HttpContext.Session property

• Session data can be configured to use different storage providers such as in-memory, distributed cache, or SQL Server

• Session data is typically used to store user-specific information like user ID, shopping ca...read more

Microservices communicate with each other through APIs, messaging queues, and service discovery.

• APIs: Microservices can communicate with each other by exposing APIs that allow them to send and receive data.

• Messaging queues: Microservices can use messaging queues like RabbitMQ or Kafka to send messages to each other asynchronously.

• Service discovery: Microservices can use service discovery tools like Consul or Eureka to locate and communicate with other services in the network....read more

Authentication is the process of verifying the identity of a user, while authorization is the process of determining what resources a user can access.

• Authentication can be done using various methods such as username/password, tokens, or biometrics.

• Authorization involves assigning roles or permissions to users based on their identity.

• Authentication and authorization are often implemented using frameworks like OAuth or JWT.

• Examples include logging in with a username and passwor...read more

C# supports different loading types, including eager, lazy, and explicit loading, each affecting performance and resource management.

• Eager Loading: Loads all related data upfront. Example: using Include() in Entity Framework.

• Lazy Loading: Loads related data on demand. Example: Navigation properties in EF that load when accessed.

• Explicit Loading: Manually loads related data. Example: using context.Entry(entity).Reference(e => e.NavigationProperty).Load();

Model binding is the process of mapping data from HTTP requests to objects in MVC and ASP.NET Core.

• Model binding automatically maps data from HTTP requests to action method parameters or properties of a model class.

• It simplifies the process of retrieving data from forms, query strings, route values, and JSON/XML payloads.

• Model binding can be customized using attributes like [Bind], [FromQuery], [FromBody], etc.

• Example: In ASP.NET Core, a POST request with form data can be aut...read more