Advanced C#

C# is a modern, object-oriented programming language developed by Microsoft. It is widely used for developing a wide range of applications, including desktop, web, and mobile applications, as well as games, and it is especially popular for developing Windows applications.

In this article, we will see some advanced and new features of C# that developers can use to write more efficient, robust, and maintainable code. We will cover topics such as Asynchronous Programming, LINQ, Delegates, Events, and more.

Asynchronous Programming:

Asynchronous Programming is a programming architecture or paradigm that allows developers to write code that doesn't block the main thread. This is especially useful in applications that require a lot of input/output (I/O) operations, such as downloading files, reading data from a database, or making network requests.

C# provides a powerful mechanism for Asynchronous Programming through the use of async/await keywords. The async keyword is used to make any method as asynchronous, while the await keyword is used to wait for the completion of an asynchronous operation.

For example, consider the following code that downloads a file synchronously:

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This code will block the main thread until the file is downloaded, which can cause the application to become unresponsive. To download the file asynchronously, we can use the async/await keywords:

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This code will not block the main thread, allowing the application to remain responsive while the file is downloaded in the background.

LINQ:

LINQ (Language Integrated Query) is a powerful feature of C# that allows developers to get the data from different data sources, such as databases, XML files, or collections, using a consistent syntax.

LINQ provides a set of operators that can be used to filter, sort, group, and project data. These operators can be combined to form complex queries that can be run against any data source that implements the IEnumerable or IQueryable interface.

For example, consider the following code that filters a list of integers to only include even numbers:

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Using LINQ, we can simplify this code to a single line:

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This code uses the Where operator to filter the list of numbers to only include even numbers, and the ToList operator to convert the result into a list.

Lambda Expressions:

Lambda Expressions are a shorthand way of writing anonymous methods. They allow you to write inline functions that can be used as arguments to other methods. Lambda Expressions are often used with Delegates and LINQ.

For example, the following code declares a Delegate and uses a Lambda Expression to instantiate it:

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Delegates:

Delegates are a type-safe, object-oriented function pointer. They are used to represent a method that can be called at a later time. Delegates are often used in event-driven programming to handle events. They are declared using the delegate keyword followed by the return type and the signature of the method they will reference.

For example, the following code declares a Delegate that references a method that takes two integers as arguments and returns an integer:

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Delegates can be instantiated with a method that has the same signature as the delegate. For example, the following code instantiates a Delegate with a method that adds two integers:

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The Delegate can then be invoked like a method:

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Extension Methods:

Extension Methods allow you to add methods to existing types without modifying their source code. They are defined as static methods in a static class, and the first parameter is decorated with the "this" keyword to indicate the type being extended.

For example, the following code defines an extension method for the string type:

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The IsPalindrome extension method can then be called on any string object:

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