How do you reset the identity start value in SQL Server?

TRUNCATE TABLE YourTableName; -- Delete all records 

DBCC CHECKIDENT ('YourTableName', RESEED, 1); -- Reset identity column 

How do electricity charges work in Telangana?

 1.If your monthly consumption is less than 100 units:

• The first 50 units will be charged at Rs. 1.95 per unit.
• The remaining 50 units will be charged at Rs. 3.10 per unit.

2. If your monthly consumption is between 100 and 200 units:

• The first 100 units will be charged at Rs. 3.40 per unit.
• The remaining 100 units will be charged at Rs. 4.80 per unit.

3. If your monthly consumption exceeds 800 units:

• The first 200 units will be charged at Rs. 5.10 per unit.
• The next 100 units (201-300) will be charged at Rs. 7.70 per unit.
• The next 100 units (301-400) will be charged at Rs. 9.00 per unit.
• The next 400 units will be charged at Rs. 9.50 per unit.
• Any remaining units beyond 800 will be charged at Rs. 10.00 per unit.

What is the difference between Public, Static, void?

1. **Public**:

   - `Public` is an access modifier in programming languages like Java or C#. It means that a method or variable can be accessed from anywhere in the program. It's like leaving the door open for anyone to use.

2. **Static**:

   - `Static` is a keyword that means something belongs to the class itself, not to instances of the class. It's like a shared resource that all instances of the class can access. You don't need an object to use it.

3. **void**:

   - `void` is a keyword used in method declarations to indicate that the method doesn't return anything. It's like a promise that the method will do something, but it won't give you anything back.

**Example** (in Java or C# ):

public class Example {

    public static void greet() {

        System.out.println("Hello, world!"); // Printing a greeting

    }

    public static void main(String[] args) {

        greet(); // Calling the greet method

    }

}

Explanation:

- `public`: This means that the `greet` method can be accessed from anywhere in the program.

- `static`: This means that the `greet` method belongs to the class itself, not to any particular instance of the class.

- `void`: This means that the `greet` method doesn't return anything. It just prints "Hello, world!" to the console when it's called.

So, when we call `greet()` in the `main` method, it prints "Hello, world!" to the console, but it doesn't return any value.

What is hoisting in JavaScript?

**Hoisting in JavaScript**:

Hoisting is like when you magically lift things up. In JavaScript, it means that declarations (like variables and functions) are lifted or brought to the top of their scope during the code execution. 

**Example**:

console.log(x); // Output: undefined

var x = 10;

Explanation:

Even though we're trying to `console.log(x)` before declaring `x`, JavaScript doesn't give an error. Instead, it "hoists" the declaration of `x` to the top, which means it's like saying `var x;` is moved to the very top of the scope:

var x;

console.log(x); // Output: undefined

x = 10;

So, when we `console.log(x)` before assigning `x` a value, it outputs `undefined` because `x` exists (it's been declared), but it hasn't been assigned a value yet.

What is the difference between let and var in JavaScript?

**Scope:**

   - `let`: Variables declared with `let` are limited to the block they are declared in. They are only accessible within the block of code where they are defined.

   - `var`: Variables declared with `var` are function-scoped or globally scoped. They are accessible throughout the entire function where they are defined, or globally if not within a function.

// Using let

function letExample() {

    let x = 10;

    if (true) {

        let y = 20;

        console.log(x); // Output: 10

        console.log(y); // Output: 20

    }

    console.log(x); // Output: 10

    console.log(y); // ReferenceError: y is not defined

}

letExample();

// Using var

function varExample() {

    var x = 10;

    if (true) {

        var y = 20;

        console.log(x); // Output: 10

        console.log(y); // Output: 20

    }

    console.log(x); // Output: 10

    console.log(y); // Output: 20 (accessible due to var's function scope)

}

varExample();

In the `letExample`, `x` is accessible within the function `letExample`, but `y` is only accessible within the `if` block where it's defined. Trying to access `y` outside the `if` block will result in a `ReferenceError`.

In the `varExample`, both `x` and `y` are accessible within the entire `varExample` function, even though `y` is defined inside the `if` block. This is because variables declared with `var` are function-scoped.

What is a LINQ query in C#?

 37. **What is a LINQ query in C#?**

    - A LINQ query is like asking a smart friend to find something for you from a big list. It's a way of asking the program to search, sort, or filter data in a flexible and easy-to-understand language.

38. **What is a tuple in C#?**

    - A tuple is like a mixed-up bag that can hold different types of things together. It's used to group multiple pieces of data into a single object.

39. **What is a CancellationToken in .NET Core?**

    - A CancellationToken is like a button you press to stop something from happening, even if it's already started. It's used to cancel tasks or operations in the program.

40. **What is a middleware in .NET Core?**

    - Middleware is like a helpful assistant that sits between the program and the outside world, handling requests and responses. It's used to add extra features or modify incoming and outgoing data.

41. **Difference between a repository and a service in .NET Core?**

    - A repository is like a specialized storehouse for data, while a service is like a helper that performs specific tasks for the program. Repositories deal with data storage and retrieval, while services handle business logic and application functionality.

42. **What is dependency injection in .NET Core?**

    - Dependency injection is like having a friend who brings you exactly what you need when you need it. It's a way of providing components or services to other parts of the program without them needing to know where those things come from.

43. **Difference between a singleton and a scoped service in .NET Core?**

    - A singleton service is like a shared resource that everyone in the program can use, while a scoped service is like a private resource that's only available to a specific part of the program. Singleton services are shared across the whole application, while scoped services are limited to a particular scope or context.

44. **Purpose of the ASP.NET Core pipeline?**

    - The ASP.NET Core pipeline is like a series of checkpoints that requests and responses pass through in a web application. It's used to handle incoming requests, process them, and send back responses, with each step adding or modifying features of the application.

45. **What is a JWT token in .NET Core?**

    - A JWT (JSON Web Token) token is like a special pass that grants access to certain parts of a web application. It's used for authentication and authorization, allowing users to prove their identity and access protected resources.

46. **What is a CORS policy in .NET Core?**

    - A CORS (Cross-Origin Resource Sharing) policy is like a set of rules that determines which websites can access resources from a web application. It's used to control access to resources from different domains and prevent unauthorized access.

47. **Purpose of the appsettings.json file in .NET Core?**

    - The appsettings.json file is like a storage space for configuration settings in a .NET Core application. It's used to store things like database connection strings, API keys, and other settings that can be easily changed without modifying the code.

48. **Purpose of the Startup.cs file in .NET Core?**

    - The Startup.cs file is like the main planner and organizer of a .NET Core application. It's responsible for configuring services, middleware, and other components needed to run the application smoothly. It's usually the first file that's executed when the application starts up.

49. **Difference between .NET Framework and .NET Core?**

    - .NET Framework is like a traditional tool that works mainly on Windows computers, while .NET Core is like a newer, more versatile tool that works on different platforms like Windows, macOS, and Linux. .NET Core is also more lightweight, open-source, and modern compared to .NET Framework.

50. **Advantages of using .NET Core?**

    - Some advantages of using .NET Core include its ability to work on different platforms, its lightweight and modular nature, being open-source, improved performance, and better support for modern web development practices like microservices and containerization.

.net core

11. **What is Entity Framework Core?**

    - Entity Framework Core is like a helper that makes it easier to talk to databases in a program. It helps the program store and get information from databases without needing to write a lot of complicated code.

12. **Difference between Code First and Database First in Entity Framework Core?**

    - Code First is like building a house from scratch based on a drawing, while Database First is like making a drawing of a house based on one that's already built. Code First starts with writing code to describe the database, while Database First starts with the existing database and creates code from it.

13. **Difference between eager loading and lazy loading in Entity Framework Core?**

    - Eager loading is like getting all the groceries you need in one trip to the store, while lazy loading is like going to the store only when you need something. Eager loading loads all the related information upfront, while lazy loading loads it only when necessary.

14. **Difference between a DbSet and a DbContext in Entity Framework Core?**

    - A DbSet is like a table in a database where you keep things, while a DbContext is like the room where you manage everything related to the database. DbSet is where you store specific types of data, while DbContext is the overall manager for dealing with the database.

15. **What is LINQ?**

    - LINQ is like a special language that helps talk to databases or lists of things in a program. It makes it easier to search, filter, or sort data without writing lots of complicated code.

16. **What is a Lambda expression in .NET Core?**

    - A Lambda expression is like a quick and simple way of writing down a small piece of code to do something specific. It's like writing a tiny recipe for a task in the program.

17. **Purpose of the using statement in C#?**

    - The using statement is like a reminder to clean up after yourself in the program. It makes sure that when you're done using something, it's put away neatly and not left lying around, which keeps the program running smoothly.

18. **Difference between an abstract class and an interface in C#?**

    - An abstract class is like a template that can do some things by itself, while an interface is like a promise to do certain things without saying how. An abstract class can do some work, while an interface just says what needs to be done.

19. **What is a delegate in C#?**

    - A delegate is like a messenger that helps different parts of the program talk to each other. It's used to pass around actions or messages between different pieces of code.

20. **Purpose of the async/await keywords in C#?**

    - The async/await keywords are like helpers that keep the program running smoothly even when it's doing something that takes a long time. They make sure the program can do other things while waiting for something to finish.

21. **What is a generic type in C#?**

    - A generic type is like a container that can hold different kinds of things inside. It's a way of making code more flexible so it can work with different types of data without being too specific.

22. **What is a nullable type in C#?**

    - A nullable type is like a box that can hold a value or nothing at all. It's used when something might not have a value and needs to be treated carefully in the program.

23. **Difference between a struct and a class in C#?**

    - A struct is like a small, simple container that holds data directly inside, while a class is like a bigger, more complex container that holds a reference to the data somewhere else. Structs are used for small, simple things, while classes are used for bigger, more complicated things.

24. **Purpose of the const keyword in C#?**

    - The const keyword is like a promise that something will never change. It's used for values that are known from the start and won't ever need to be different during the program's run.

25. **Difference between a static class and a non-static class in C#?**

    - A static class is like a clubhouse where everyone can hang out, but there's only one of them and nobody can change it. A non-static class is like a clubhouse where each person has their own space and can make changes to it.

26. **Purpose of the lock keyword in C#?**

    - The lock keyword is like a security guard that keeps track of who's using something important in the program. It makes sure that only one thing can use it at a time to avoid problems.

27. **Difference between the StringBuilder and String classes in C#?**

    - StringBuilder is like a special tool for building big, complicated strings quickly and efficiently, while String is like a box that holds a string but can't be changed once it's made.

28. **Purpose of the yield keyword in C#?**

    - The yield keyword is like a magician's trick for making a list of things appear one by one as needed. It helps generate a sequence of items without having to create them all at once.

29. **What is garbage collection in .NET Core?**

    - Garbage collection is like a cleanup crew that goes around the program, picking up things that are no longer needed and making sure everything stays tidy and efficient.

30. **Difference between a value type and a reference type in .NET Core?**

    - A value type is like a box that holds something directly inside, while a reference type is like a signpost that points to where something is stored. Value types are usually smaller and faster, while reference types are more flexible.

31. **Purpose of the using directive in C#?**

    - The using directive is like a shortcut that tells the program where to find certain things it needs. It helps avoid writing long, complicated names for things every time they're used.

32. **What is a try-catch block in C#?**

    - A try-catch block is like a safety net that catches mistakes before they cause big problems. It lets the program try something risky, but if it goes wrong, it's ready to handle the situation without crashing.

33. **Purpose of the finally block in a try-catch-finally statement in C#?**

    - The finally block is like a cleanup crew that always shows up, no matter what happened before. It's used to make sure everything is put back the way it should be, even if something went wrong.

34. **What is a lambda expression in C#?**

    - A lambda expression is like a secret code that describes a small, specific task in the program. It's a quick way of writing down what needs to be done without making a big fuss about it.

35. **What is an extension method in C#?**

    - An extension method is like a special tool that adds extra functionality to something that already exists. It's used to make existing things more useful without changing them directly.

36. **Difference between a synchronous and asynchronous method in C#?**

    - A synchronous method is like doing things step by step, one after the other, while an asynchronous method is like doing multiple things at once, without waiting for each one to finish before starting the next.

What is .NET Core

1. **What is .NET Core?**

   - .NET Core is like a toolbox that helps build modern computer programs that can work on different types of computers, like Windows, Mac, or Linux.

2. **Advantages of .NET Core?**

   - It's like using a super handy tool that makes building programs easier because it works on different types of computers, it's fast, open to everyone, easy to update, and lots of people know how to use it.

3. **Difference between .NET Framework and .NET Core?**

   - Think of .NET Framework as a tool that only works on Windows computers, while .NET Core is like a more flexible tool that works on Windows, Mac, and Linux. .NET Core also doesn't need as much stuff to run as .NET Framework.

4. **Difference between ASP.NET and ASP.NET Core?**

   - ASP.NET is an older way of making websites, like using an older tool, while ASP.NET Core is a newer, more modern way that's faster and works on different computers.

5. **How does dependency injection work in .NET Core?**

   - Dependency injection is like having a friend who gives you exactly what you need when you need it. In .NET Core, it's a way for parts of a program to get what they need without having to ask for it directly.

6. **Role of the Startup.cs file in .NET Core?**

   - The Startup.cs file is like the boss who decides what tools the program needs and how they should be used. It gets things ready when the program starts.

7. **Difference between middleware and filters in .NET Core?**

   - Middleware is like a helper that stands between the program and the outside world, while filters are like special helpers that change things when information goes in or out of the program.

8. **Purpose of appsettings.json file in .NET Core?**

   - It's like a list of rules and settings for the program, such as what to do when connecting to a database or what secret codes to use.

9. **Purpose of the wwwroot folder in .NET Core?**

   - It's like a storage room for files that the program needs, like pictures or styles, that anyone using the program can access easily.

10. **Difference between Razor Pages and MVC in .NET Core?**

    - Razor Pages is like an easy way of making simple websites, while MVC is a bit more complex and good for bigger projects.

different type of collections in c#

In C#, collections provide a flexible way to work with groups of objects. Let’s explore the different types of collections:

1. Indexed-Based Collections:

   • These collections allow you to access elements by their index (position). Some common indexed-based collection types include:
     • Array: A fixed-size collection of elements of the same type.
     • ArrayList: A dynamically resizable collection that can hold elements of different types.
     • List<T>: A generic list that provides type safety and dynamic resizing.
     • Queue: A first-in-first-out (FIFO) collection.
     • ConcurrentQueue<T>: A thread-safe version of the queue.
     • Stack: A last-in-first-out (LIFO) collection.
     • ConcurrentStack<T>: A thread-safe version of the stack.
     • LinkedList<T>: A doubly linked list.

2. Key-Value Pair Collections:

   • These collections store elements as key-value pairs. Each element has both a key and a value. Common key-value pair collection types include:
     • Hashtable: A non-generic collection that uses hash codes for fast lookups.
     • SortedList: A sorted version of the Hashtable.
     • SortedList<TKey, TValue>: A generic sorted collection.
     • Dictionary<TKey, TValue>: A generic dictionary with fast key-based access.
     • ConcurrentDictionary<TKey, TValue>: A thread-safe version of the dictionary.

3. Specialized Collections:

   • These collections serve specific purposes and have unique features:
     • KeyedCollection<TKey, TItem>: Combines list and dictionary behavior, allowing access by both index and key.
     • ReadOnlyCollectionBase: Provides a base class for creating read-only collections.
     • CollectionBase: A base class for creating strongly typed collections.
     • DictionaryBase: A base class for creating custom dictionaries.

4. Strong Typing and Generics:

   • Generic collections (such as List<T>, Dictionary<TKey, TValue>, etc.) are the best solution for strong typing. They ensure type safety at compile time.
   • If your language does not support generics, you can extend abstract base classes (like CollectionBase) to create strongly typed collections.

5. LINQ with Collection Types:

   • LINQ (Language Integrated Query) allows concise and powerful querying of in-memory objects.
   • LINQ queries can filter, order, and group data, improving performance.
   • Use LINQ with any type that implements IEnumerable or IEnumerable<T>.

Remember to choose the appropriate collection type based on your specific requirements! 

What is Interface

 Definition:

"An interface in object-oriented programming is a collection of abstract methods. It defines a contract for classes that implement it, specifying the methods that must be present in those classes. Unlike classes, an interface doesn't provide any implementation for the methods; it only declares their signatures. Classes that implement an interface must provide concrete implementations for all the methods declared in the interface."

Key Points:

1. Abstract Methods:

   • "Interfaces consist of abstract methods, which are methods without a body. These methods serve as a blueprint for any class that implements the interface."

2. Contract:

   • "An interface establishes a contract between the interface and the implementing classes. It specifies what methods the implementing classes must have, but it doesn't dictate how these methods should be implemented."

3. Multiple Inheritance:

   • "One significant advantage of interfaces is that a class can implement multiple interfaces. This supports a form of multiple inheritance, allowing a class to inherit the method signatures from multiple sources."

4. Example:

   • "For instance, consider an interface Drawable with a method draw(). Any class that implements this interface must provide its own implementation of the draw() method. This ensures a consistent way of drawing for various objects."

Use in Programming:

• "Interfaces are used to achieve abstraction and ensure code consistency in large codebases."
• "They are crucial in scenarios where multiple classes need to share a common set of methods without having a common base class."

When to Use Interfaces:

• "Use interfaces when you want to define a contract that multiple classes can adhere to without specifying the implementation details."
• "Interfaces are beneficial in scenarios where you want to achieve loose coupling between components in your system."