600+ DOT NET Developer Interview Questions and Answers

Primary key uniquely identifies each record in a table. It cannot be null and there can be only one primary key.

• Primary key ensures each record in a table is unique

• Primary key cannot have null values

• Only one primary key can be defined for a table

• Primary key can be a single column or a combination of columns

Stored procedures are precompiled SQL queries stored in the database, while functions are user-defined routines that return a value.

• Stored procedures are used for performing specific tasks or operations on the database, while functions are used to return a single value.

• Stored procedures can contain multiple SQL statements and can have input and output parameters, while functions are more limited in their functionality.

• Stored procedures are generally used for complex business ...read more

Divide array in two halves and keep each half in ascending order without using new Array.

• Use Array.sort() method to sort the original array

• Use Array.slice() method to divide the array into two halves

• Use Array.reverse() method to reverse the second half of the array

HTML helpers are methods that help in rendering HTML in a view. Yes, we can create custom HTML helpers.

• HTML helpers are methods that generate HTML markup in a view.

• They help in reducing the amount of HTML code that needs to be written in a view.

• Custom HTML helpers can be created by defining extension methods on the HtmlHelper class.

• Custom HTML helpers can be useful for generating reusable HTML components or complex HTML markup.

• Example: Creating a custom HTML helper to generat...read more

Query to find 4th highest salary

• Use the 'ROW_NUMBER' function to assign a rank to each salary

• Order the salaries in descending order

• Select the salary with rank 4

No, static constructors cannot have multiple arguments.

• Static constructors in C# do not take any arguments.

• They are used to initialize static data members or perform any necessary setup for the class.

• Example: public static MyClass() { // constructor code }

Yes, we can write multiple stored procedures inside stored procedures. Functions can also be written inside stored procedures.

• Yes, you can call one stored procedure from another stored procedure.

• You can also define and call functions inside a stored procedure.

• Example: CREATE PROCEDURE spOuter AS BEGIN CREATE PROCEDURE spInner AS ... END; END;

• Example: CREATE PROCEDURE spOuter AS BEGIN CREATE FUNCTION fnInner() RETURNS ... AS ... END; END;

Globalization is the process of designing and developing applications that can be used in multiple languages and cultures.

• Use resource files to store text in different languages

• Use Unicode encoding to support different character sets

• Use culture-specific formatting for dates, times, and numbers

• Test the application with different languages and cultures to ensure proper functionality

Data table is a single table while dataset is a collection of tables.

• Data table is a single table that represents a single database table.

• Dataset is a collection of tables that can hold multiple tables from different databases.

• Data table can be used to store and manipulate data from a single table.

• Dataset can be used to store and manipulate data from multiple tables.

• Data table is a part of dataset.

• Dataset can hold multiple data tables.

Integrating third party web APIs involves obtaining API key, making HTTP requests, parsing responses, and handling errors.

• Obtain API key from third party provider

• Make HTTP requests to the API endpoints

• Parse the JSON/XML response data

• Handle errors and exceptions gracefully

Compile time binding occurs during compilation while runtime binding occurs during execution.

• Compile time binding is also known as early binding, where the method to be called is determined at compile time based on the type of the object.

• Runtime binding is also known as late binding, where the method to be called is determined at runtime based on the actual type of the object.

• Compile time binding is faster as it is done during compilation, while runtime binding is slower as i...read more

You can change the layout page during runtime by dynamically setting the layout property in the code behind.

• Set the layout property in the code behind based on certain conditions or user input.

• Use conditional statements to determine which layout page to use.

• Example: if(userRole == 'admin') { Layout = '~/Views/Shared/_AdminLayout.cshtml'; } else { Layout = '~/Views/Shared/_UserLayout.cshtml'; }

Inheritance is a mechanism in OOP where a class inherits properties and behaviors from another class.

• Inheritance allows a class to reuse code from another class.

• Types of inheritance include single inheritance, multiple inheritance, multilevel inheritance, hierarchical inheritance, and hybrid inheritance.

• Example: Class B inheriting from Class A - B is a subclass of A.

Method overloading is when multiple methods have the same name but different parameters. Method overriding is when a subclass provides a specific implementation of a method that is already provided by its parent class.

• Method overloading allows a class to have multiple methods with the same name but different parameters.

• Method overriding occurs in a subclass when a method has the same name and parameters as a method in its superclass.

• Method overloading is resolved at compile t...read more

Delete removes rows one by one and can be rolled back, while Truncate removes all rows at once and cannot be rolled back.

• Delete is a DML command while Truncate is a DDL command.

• Delete can be rolled back using a transaction, while Truncate cannot be rolled back.

• Delete fires triggers on each row deletion, while Truncate does not fire triggers.

• Delete is slower as it removes rows one by one, while Truncate is faster as it removes all rows at once.

• Delete maintains the identity of ...read more

NET core is a cross-platform, open-source framework for building modern, cloud-based, internet-connected applications. NET framework is a Windows-only framework for building Windows desktop applications. NET is a general term encompassing both .NET core and .NET framework.

• NET core is cross-platform and open-source, while .NET framework is Windows-only.

• .NET core is modular and lightweight, allowing for faster performance and easier updates.

• .NET core is designed for building mo...read more

Clustered index physically reorders the data in the table while non-clustered index creates a separate structure.

• Clustered index determines the physical order of data rows in a table.

• Non-clustered index creates a separate structure to store the index data.

• A table can have only one clustered index but multiple non-clustered indexes.

• Clustered index is faster for retrieval but slower for insert and update operations.

• Non-clustered index is slower for retrieval but faster for inse...read more

MVC stands for Model-View-Controller. It is a software architectural pattern used in web development.

• MVC separates the application into three interconnected components: Model, View, and Controller.

• Model represents the data and business logic of the application.

• View is responsible for rendering the user interface.

• Controller handles user input, updates the model, and interacts with the view.

• MVC follows a specific life cycle: Request is received, routing determines the appropria...read more

There are various types of constraints in DOT NET development, including primary key, foreign key, unique, check, and default constraints.

• Primary key constraints ensure each record in a table is unique.

• Foreign key constraints enforce referential integrity between tables.

• Unique constraints ensure that all values in a column are distinct.

• Check constraints validate the data before it is inserted or updated.

• Default constraints provide a default value for a column if no value is s...read more

Independent class can be instantiated while abstract class cannot be instantiated directly.

• Independent class can be directly instantiated using the 'new' keyword.

• Abstract class cannot be instantiated directly, it can only be used as a base class for other classes.

• Independent class does not require any derived class to implement its members.

• Abstract class can have abstract methods that must be implemented by derived classes.

Interfaces are contracts that define a set of methods and properties that a class must implement.

• Interfaces provide a way to achieve abstraction and polymorphism in object-oriented programming.

• They allow for loose coupling between classes and promote code reusability.

• Interfaces can be used to define common behavior across multiple classes.

• Example: IDisposable interface in C# ensures that an object can be properly disposed of when it is no longer needed.

• Example: IComparable in...read more

SELECT is used to retrieve data, DELETE is used to remove data, and UPDATE is used to modify data in SQL.

• SELECT is used to retrieve specific data from a database table.

• DELETE is used to remove specific data from a database table.

• UPDATE is used to modify existing data in a database table.

• Examples: SELECT * FROM table_name, DELETE FROM table_name WHERE condition, UPDATE table_name SET column_name = value WHERE condition

ViewBag, ViewData, and TempData are ways to pass data between controllers and views in ASP.NET.

• ViewBag is a dynamic property that allows you to pass data from the controller to the view. It uses dynamic typing.

• ViewData is a dictionary object that allows you to pass data from the controller to the view. It requires typecasting.

• TempData is a dictionary object that allows you to pass data from one controller to another or from one action to another.

• ViewBag and ViewData are used ...read more

Stored procedures, string vs string builder, triggers, query performance, indexes, validations, and common table expressions in DOT NET development.

• Stored procedures are precompiled SQL queries stored in the database for reuse and performance optimization.

• String builder is more efficient for concatenating large strings compared to regular string concatenation.

• Triggers are database objects that automatically perform actions when certain events occur in the database.

• Query perfo...read more

The optimal solution approach for the Travelling Salesman Problem involves using algorithms such as the Nearest Neighbor Algorithm and the 2-Opt Algorithm.

• The Nearest Neighbor Algorithm starts at a random city and selects the nearest unvisited city as the next stop.

• The 2-Opt Algorithm involves swapping two edges in the tour to see if it results in a shorter distance.

• Other algorithms include the Genetic Algorithm and the Simulated Annealing Algorithm.

• The optimal solution is no...read more

Access modifiers are keywords in programming languages that define the accessibility of classes, methods, and other members.

• Types of access modifiers in C# are public, private, protected, internal, protected internal.

• Public - accessible from any other class.

• Private - accessible only within the same class.

• Protected - accessible within the same class or derived classes.

• Internal - accessible within the same assembly.

• Protected Internal - accessible within the same assembly or der...read more

Implementing a new feature to automate data migration process

• Developing a custom data migration tool using C# and SQL Server

• Creating scripts to extract data from legacy system and load into new system

• Testing the tool with sample data to ensure accuracy and efficiency