C# Extension Methods

Add new methods to existing types without modifying original source code.

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Extension methods enable you to "add" methods to existing types without creating a new derived type, recompiling, or modifying the original type. Declared as static methods using this.

Key Takeaways: C# Extension Methods

Mastering C# Extension Methods helps you write clean and reliable C# code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.

C# Extension Methods Code Example

using System;

public static class StringExtensions {
    public static int WordCount(this string str) {
        return str.Split(' ', StringSplitOptions.RemoveEmptyEntries).Length;
    }
}

class Program {
    static void Main() {
        string text = "CodesInTech Software Consultancy";
        Console.WriteLine($"Word count: {text.WordCount()}");
    }
}

Output

Word count: 3

Run this example on your own computer. The "Get Started" lesson shows how to set it up.

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C# Extension Methods

💡 Key Takeaways: C# Extension Methods

C# Extension Methods Code Example

Key Takeaways: C# Extension Methods