Junior .NET Developer
50+ Junior .NET Developer Interview Questions and Answers
Q1. what is StringBuffer and were is use
StringBuffer is a mutable sequence of characters. It is used to efficiently manipulate strings.
StringBuffer is a class in Java that allows you to modify strings without creating a new object.
It is used when you need to concatenate a large number of strings efficiently.
StringBuffer is synchronized, so it is safe to use in multi-threaded environments.
It provides methods like append(), insert(), delete(), and reverse() to modify the string.
Example: StringBuffer sb = new StringBu...read more
Q2. What is ArrayList where is used
ArrayList is a dynamic array that can store objects of any type. It is used to store and manipulate collections of data.
ArrayList is part of the System.Collections namespace in .NET.
It can store objects of any type, including value types and reference types.
It automatically resizes itself as elements are added or removed.
Elements can be accessed by their index.
It provides methods for adding, removing, and searching for elements.
Example: ArrayList names = new ArrayList(); name...read more
Junior .NET Developer Interview Questions and Answers for Freshers
Q3. Coding round 1. Write a code for prime and odd numbers
Code for prime and odd numbers
For prime numbers, check if the number is divisible by any number less than itself
For odd numbers, check if the number is not divisible by 2
Use loops and conditional statements to implement the checks
Consider edge cases such as negative numbers and 0
Q4. What is generic how to declare
Generics in .NET allow you to create reusable code that can work with different types.
Generics are declared using the 'generic' keyword followed by the type parameter(s) in angle brackets.
Example: 'public class MyGenericClass
{}' You can use multiple type parameters separated by commas.
Example: 'public class MyGenericClass
{}' Generics provide type safety and eliminate the need for casting.
Example: 'List
myList = new List ();'
Q5. Do you know SQL, What Databases are you familiar with?
Yes, I know SQL and I am familiar with various databases.
I have experience in writing SQL queries for Microsoft SQL Server, MySQL, and Oracle databases.
I am familiar with database design, normalization, and indexing.
I have worked with Entity Framework and LINQ to SQL for database access in .NET applications.
Q6. why we use interface and abstract methods?
Interfaces and abstract methods are used to achieve abstraction and provide a blueprint for classes to implement.
Interfaces allow for multiple inheritance and provide a contract for classes to adhere to.
Abstract methods define a method signature without implementation, allowing subclasses to provide their own implementation.
Interfaces and abstract methods promote code reusability and maintainability.
Interfaces can be used to achieve loose coupling and dependency injection.
Exa...read more
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Q7. Find second highest salary,Oops concept what is asp.net core and difference.
Answering interview questions on finding second highest salary, OOPs concepts, and ASP.NET Core.
To find the second highest salary, we can use the SQL query 'SELECT MAX(salary) FROM employees WHERE salary < (SELECT MAX(salary) FROM employees)'.
OOPs concepts include inheritance, polymorphism, encapsulation, and abstraction.
ASP.NET Core is a cross-platform, open-source framework for building modern web applications.
The main difference between ASP.NET and ASP.NET Core is that ASP...read more
Q8. Why used isPostBack property in pageload event?
The isPostBack property is used in the Page_Load event to determine if the page is being loaded for the first time or if it is a postback.
The isPostBack property is a boolean property that indicates whether the page is being loaded for the first time or if it is a postback.
It is commonly used to differentiate between the initial page load and subsequent postbacks.
This property is useful when you want to perform certain actions only on the initial page load and not on postback...read more
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Q9. What is dependency injection and its lifetimes
Dependency injection is a design pattern where components are given their dependencies rather than creating them.
Dependency injection helps in making components loosely coupled, making it easier to test and maintain code.
There are three main lifetimes for dependencies: transient, scoped, and singleton.
Transient dependencies are created each time they are requested.
Scoped dependencies are created once per request.
Singleton dependencies are created only once and reused througho...read more
Q10. What is the diffrence between Abstract vs interface?
Abstract classes can have both abstract and non-abstract methods, while interfaces can only have abstract methods.
Abstract classes can have constructors, fields, and properties, while interfaces cannot.
A class can inherit from only one abstract class, but can implement multiple interfaces.
Abstract classes are used when a class needs to provide a default implementation for some methods, while interfaces are used to define a contract for classes to implement.
Example: Abstract c...read more
Q11. what is CORS ? and we use this
CORS stands for Cross-Origin Resource Sharing, a security feature that allows servers to specify who can access their resources.
CORS is used to prevent web pages from making requests to a different domain than the one that served the original page.
It is implemented using HTTP headers like Access-Control-Allow-Origin.
CORS is commonly used in web development to enable secure cross-origin requests in browsers.
Example: If a frontend application on domain A wants to make a request...read more
Q12. Difference between connected and disconnected architecture of ADO. NET
Connected architecture maintains a continuous connection to the database while disconnected architecture connects only when required.
Connected architecture is suitable for applications that require real-time data updates.
Disconnected architecture is suitable for applications that require occasional data updates.
Connected architecture uses DataReader while disconnected architecture uses DataSet.
Connected architecture is faster but consumes more resources than disconnected arch...read more
Q13. What is auto mapper,middleware, opps conceps
AutoMapper is a library for mapping objects, middleware is software that acts as a bridge between different systems, OOPs concepts are principles of object-oriented programming.
AutoMapper is a popular object-to-object mapping library in .NET that helps to eliminate repetitive mapping code.
Middleware in .NET is software that can handle requests and responses between a client and a server, providing additional functionalities like logging, authentication, etc.
OOPs concepts in ....read more
Q14. How to implement multiple inheritance in C#
Multiple inheritance is not directly supported in C#, but can be achieved using interfaces.
C# does not support multiple inheritance of classes due to the Diamond Problem
Multiple inheritance can be achieved using interfaces by implementing multiple interfaces in a class
Example: public class MyClass : Interface1, Interface2 { }
Q15. why we use TFS or GitHub?
TFS and GitHub are used for version control and collaboration in software development.
TFS and GitHub provide version control, allowing developers to track changes and collaborate on code.
They enable multiple developers to work on the same codebase simultaneously, avoiding conflicts.
They offer features like branching and merging, making it easier to manage different versions of code.
TFS and GitHub provide a centralized repository for code, ensuring its availability and backup....read more
Q16. What are DDL and DML queries?
DDL and DML are SQL queries used to manipulate databases. DDL is used to create, modify or delete database objects while DML is used to manipulate data.
DDL stands for Data Definition Language and is used to create, modify or delete database objects like tables, indexes, etc.
DML stands for Data Manipulation Language and is used to manipulate data in the database like inserting, updating or deleting records.
DDL queries include CREATE, ALTER and DROP statements while DML queries...read more
Q17. Write a code for reverse string
Code to reverse a string
Create an empty string variable to store the reversed string
Loop through the original string from the end to the beginning
Append each character to the empty string variable
Return the reversed string
Q18. What are the advantages of Dotnet Core?
Dotnet Core offers improved performance, cross-platform compatibility, and open-source flexibility.
Improved performance compared to traditional .NET Framework
Cross-platform compatibility allows for development on Windows, macOS, and Linux
Open-source flexibility enables community contributions and faster updates
Support for microservices architecture and containerization
Enhanced security features and easier deployment options
Q19. CLASS NAMES IN disconnected architecture
In disconnected architecture, class names should reflect the entities or objects they represent.
Class names should be meaningful and descriptive.
They should follow naming conventions, such as PascalCase or camelCase.
Avoid using abbreviations or acronyms that may not be easily understood.
Consider using domain-specific terminology to make the class names more intuitive.
Examples: Customer, Order, Product, Employee
Q20. which technical languages do you know?
I am proficient in C#, SQL, and JavaScript.
C#
SQL
JavaScript
Q21. 3. Write a code for fibannoci series
Code for Fibonacci series
Declare two variables to store the first two numbers of the series
Use a loop to generate the next numbers in the series by adding the previous two
Print or store the generated numbers
Q22. What is use of delegate?
Delegates are used to create references to methods and pass them as arguments to other methods.
Delegates allow for loose coupling between objects
Delegates can be used to implement callbacks and event handlers
Delegates can be used to implement the observer pattern
Delegates can be used to implement the command pattern
Delegates can be used to implement the strategy pattern
Q23. What are filters
Filters in .NET are used to perform logic before or after an action method is executed.
Filters can be used for authorization, logging, exception handling, etc.
Examples include AuthorizeFilter, ActionFilter, ExceptionFilter, ResultFilter.
Filters can be applied globally, at controller level, or at action level.
Q24. How to implement abstract classes
Abstract classes in C# provide a way to define common behavior for derived classes while allowing specific implementations.
Use the 'abstract' keyword to define an abstract class.
Abstract classes cannot be instantiated and can contain abstract methods that must be implemented by derived classes.
Derived classes must provide implementations for all abstract methods.
Abstract classes can also have non-abstract methods and properties.
Example: abstract class Shape { public abstract ...read more
Q25. Are you familiar with Angular?
Yes, Angular is a popular front-end framework for building web applications.
Angular is developed and maintained by Google.
It uses TypeScript for building applications.
It follows the MVC (Model-View-Controller) architecture.
It provides features like two-way data binding, dependency injection, and directives.
Examples of popular Angular applications include Gmail, PayPal, and Upwork.
Q26. Difference between authentication, authorization
Authentication verifies the identity of a user, while authorization determines what actions a user is allowed to perform.
Authentication confirms the user's identity through credentials like username and password.
Authorization controls the access rights of authenticated users to specific resources or actions.
Example: Logging into a website with a username and password is authentication. Accessing certain pages or features based on user roles is authorization.
Q27. What is join?
Join is a SQL operation that combines rows from two or more tables based on a related column between them.
Join is used to retrieve data from multiple tables in a single query.
Common types of joins include inner join, left join, right join, and full outer join.
Join conditions are specified using the ON keyword followed by the columns to join on.
Example: SELECT * FROM table1 JOIN table2 ON table1.column = table2.column;
Q28. Function and View In sql server
Functions and views are used in SQL Server to encapsulate logic and simplify querying.
Functions are reusable blocks of code that can accept parameters and return a value.
Views are virtual tables that are based on the result set of a SELECT query.
Functions can be scalar functions, table-valued functions, or aggregate functions.
Views can be used to simplify complex queries by encapsulating logic and joining multiple tables.
Functions and views can improve performance by reducing...read more
Q29. What is the full form of SQL
Structured Query Language
SQL stands for Structured Query Language
It is a standard language for accessing and manipulating databases
Commonly used for querying, updating, and managing relational databases
Examples include SELECT, INSERT, UPDATE, DELETE statements
Q30. What are middlewares?
Middlewares are components that handle requests and responses in the pipeline of a web application.
Middlewares are software components that are executed in the request-response pipeline of a web application.
They can intercept, process, or modify incoming requests and outgoing responses.
Examples include authentication middleware, logging middleware, and error handling middleware.
Q31. What is Partial Class?
Partial class is a class that can be split into multiple files, allowing different parts of the class to be defined in different files.
Partial classes are useful for organizing large classes and separating different concerns.
All parts of a partial class must use the 'partial' keyword.
When compiled, all parts of a partial class are combined into a single class definition.
Q32. What is class and object?
A class is a blueprint for creating objects, while an object is an instance of a class.
A class defines the properties and behaviors of objects.
An object is created based on a class, and can have its own unique values for the properties defined in the class.
Example: Class 'Car' may have properties like 'color' and 'model', while an object of class 'Car' could be 'red Ferrari'.
Q33. Signature of multicaste delegate
Signature of multicast delegate
A multicast delegate is a delegate that can have multiple methods assigned to it
The signature of a multicast delegate is the same as that of a regular delegate
The signature includes the return type, name, and parameters of the delegate
Q34. Difference between Function and Method
A function is a standalone block of code that performs a specific task, while a method is a function that is associated with a class or object.
Functions are independent and can be called from anywhere in the code.
Methods are associated with a class or object and are called using the dot notation.
Functions can be defined outside of classes, while methods are defined within classes.
Example: Function to calculate the square root of a number vs Method to calculate the area of a r...read more
Q35. Difference between first, single
First returns the first element of a sequence, while Single returns the only element of a sequence or throws an exception if there is not exactly one element.
First is used to retrieve the first element of a sequence, while Single is used to retrieve the only element of a sequence.
First does not throw an exception if there are no elements in the sequence, while Single throws an exception in this case.
Example: var numbers = new List
{ 1, 2, 3 }; var firstNumber = numbers.First(...read more
Q36. Difference between ref, out params
ref and out are both used for passing arguments by reference in C#, but out parameters are not required to be initialized before being passed.
ref parameters must be initialized before being passed to a method, while out parameters do not need to be initialized
out parameters are typically used for returning multiple values from a method
ref parameters can be used for both input and output, while out parameters are typically used for output only
Q37. Realtime example of static class
A static class is a class that cannot be instantiated and is used to group related methods and properties.
Static classes are commonly used for utility classes that contain helper methods.
They are also used for defining extension methods.
Example: Math class in C# contains static methods like Math.Max() and Math.Min().
Q38. Choosing Norm software
Norm software should be chosen based on its compatibility with the organization's existing systems and its ability to meet specific business needs.
Consider the software's compatibility with existing systems
Evaluate the software's ability to meet specific business needs
Assess the software's ease of use and user interface
Research the software's reputation and customer reviews
Compare the software's pricing and licensing options
Q39. What was polimorphism
Polymorphism is the ability of an object to take on many forms.
Polymorphism allows objects of different classes to be treated as objects of a common superclass.
There are two types of polymorphism: compile-time (method overloading) and runtime (method overriding).
Example: Animal class with methods like eat() can be inherited by classes like Dog and Cat, which can override the eat() method.
Polymorphism helps in achieving flexibility and extensibility in object-oriented programm...read more
Q40. What is interface
An interface in .NET is a reference type that defines a contract for classes to implement certain methods and properties.
Interfaces contain method signatures but no implementation.
Classes can implement multiple interfaces.
Interfaces are used for achieving abstraction and multiple inheritance in .NET.
Example: 'IComparable' interface in C# is used for comparing objects.
Q41. What is datatype?
Datatype is a classification of data which tells the compiler or interpreter how the programmer intends to use the data.
Datatypes specify the type of data that a variable can hold.
Examples include int (integer), string (text), bool (boolean), etc.
Different programming languages have different datatypes and rules for their usage.
Q42. What is inheritance?
Inheritance is a concept in object-oriented programming where a class inherits properties and behaviors from another class.
Allows for code reusability by creating a new class based on an existing class
Derived class (child class) inherits attributes and methods from a base class (parent class)
Example: Class Car can inherit properties like color and methods like drive from class Vehicle
Q43. What is Dependency Injection
Dependency Injection is a design pattern where the dependencies of an object are provided externally rather than created within the object itself.
Allows for better code reusability and testability
Reduces coupling between classes
Promotes separation of concerns
Example: Instead of creating a database connection within a class, the connection is injected into the class through a constructor or property
Q44. What is array
An array is a collection of similar data types stored in contiguous memory locations.
Arrays can be of any data type, including integers, floats, and objects.
Arrays are indexed starting from 0.
Arrays can be multidimensional, such as a 2D array.
Arrays can be dynamically resized using methods like Append or Resize.
Example: string[] names = {"John", "Jane", "Bob"};
Q45. Oop Concept with example
OOP stands for Object-Oriented Programming, a programming paradigm based on the concept of objects.
OOP focuses on creating objects that contain both data and methods to manipulate that data.
Encapsulation, inheritance, and polymorphism are key principles of OOP.
Example: Creating a 'Car' class with properties like 'make', 'model', and methods like 'startEngine' and 'drive'.
Q46. What is Windows.load
Windows.load is not a standard term in .NET development. It may refer to a custom function or method used in a specific application.
Windows.load is not a built-in function in .NET framework
It could be a custom function created by a developer for specific purposes
Without more context, it is difficult to provide a specific answer
Q47. Program to Reverse a number
Program to reverse a number
Convert the number to a string
Reverse the string using a loop or built-in function
Convert the reversed string back to a number
Q48. Type of Constructor
Constructors are special methods in a class used to initialize objects. They have the same name as the class.
Constructors are used to initialize objects of a class.
They have the same name as the class.
They do not have a return type.
They can be parameterized or default constructors.
Example: public class Person { public Person(string name) { } }
Q49. Reverse the string
Reverse a given string
Use a loop to iterate through the characters of the string and build a new string in reverse order
Alternatively, use built-in functions like Array.Reverse() in C#
Consider edge cases like empty string or null input
Q50. Mvc type and explain
MVC is a software architectural pattern used in web development to separate the application into three main components: Model, View, and Controller.
Model: Represents the data and business logic of the application.
View: Represents the UI of the application, what the user sees and interacts with.
Controller: Acts as an intermediary between the Model and View, handling user input and updating the Model accordingly.
Example: In an MVC application, a user interacts with the View (a ...read more
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