C# Academy · Lesson

Working with Strings

Manipulate and process text using C#'s powerful string handling features.

Lesson 5 of 510 steps

Working with Strings is a free C# Academy lesson on CoddyKit. This is lesson 5 of 5. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the C# Academy learning path, and your progress syncs across the web and the CoddyKit app. The C# Academy course includes 5 lessons in total.

Introduction to Strings

Working with Strings

Welcome to the next lesson! In this lesson, you’ll learn how to use and manipulate strings in C#, one of the most versatile and essential data types in programming. Let’s get started!

What Are Strings?

A string is a sequence of characters, such as text, enclosed in double quotes. In C#, strings are objects of the System.String class and come with many built-in methods for manipulation.

Example: "Hello, World!" is a string.

Key Point: Strings are immutable, meaning their content cannot be changed after creation.

Declaring Strings

You can declare and initialize strings like this:

Tip: Use double quotes (") to enclose string values.

using System;

class Program {
    static void Main() {
        string greeting = "Hello, World!"; 
// Declare and initialize a string
        Console.WriteLine(greeting); 
// Outputs: Hello, World!
    }
}

Concatenating Strings

You can combine two or more strings using the + operator or the String.Concat() method. Example:

Key Point: Concatenation is a common operation when working with strings.

using System;

class Program {
    static void Main() {
        string firstName = "John";
        string lastName = "Doe";

        string fullName = firstName + " " + lastName; // Concatenation using +
        Console.WriteLine("Full Name: " + fullName);

        string fullNameUsingConcat = String.Concat(firstName, " ", lastName); // Using String.Concat()
        Console.WriteLine("Full Name (Concat): " + fullNameUsingConcat);
    }
}

String Interpolation

String interpolation allows you to embed expressions directly into a string. Example:

Tip: Use the $ symbol before the string to enable interpolation.

using System;

class Program {
    static void Main() {
        string name = "Alice";
        int age = 25;

        string message = $"Hello, my name is {name} and I am {age} years old.";
        Console.WriteLine(message); 
       // Outputs: Hello, my name is Alice and I am 25 years old.
    }
}

Common String Methods

Strings in C# come with several built-in methods. Examples:

Key Point: Use these methods to manipulate strings efficiently.

using System;

class Program {
    static void Main() {
        string text = "   C# Programming   ";

        Console.WriteLine("Original: '" + text + "'");
        Console.WriteLine("Trimmed: '" + text.Trim() + "'"); 
// Removes leading and trailing spaces
        Console.WriteLine("Uppercase: " + text.ToUpper()); 
// Converts to uppercase
        Console.WriteLine("Lowercase: " + text.ToLower()); 
// Converts to lowercase
        Console.WriteLine("Length: " + text.Length); // Gets the length of the string
    }
}

Splitting and Joining Strings

You can split a string into an array of substrings or join an array into a single string. Example:

Tip: Use Split() and Join() for advanced string operations.

using System;

class Program {
    static void Main() {
        string sentence = "C# is fun to learn";

        // Splitting
        string[] words = sentence.Split(' '); // Splits the sentence by spaces
        Console.WriteLine("Words:");
        foreach (string word in words) {
            Console.WriteLine(word);
        }

        // Joining
        string joined = String.Join("-", words); // Joins words with a hyphen
        Console.WriteLine("Joined: " + joined); // Outputs: C#-is-fun-to-learn
    }
}

Practice Challenge

Write a program that takes a full name as input, splits it into first and last name, and displays them separately. Example:

using System;

class Program {
    static void Main() {
        Console.WriteLine("Enter your full name:");
        string fullName = Console.ReadLine();

        string[] names = fullName.Split(' ');
        Console.WriteLine("First Name: " + names[0]);
        if (names.Length > 1) {
            Console.WriteLine("Last Name: " + names[1]);
        } else {
            Console.WriteLine("Last Name: Not provided");
        }
    }
}

Great Job!

Congratulations! You’ve learned how to declare, concatenate, manipulate, and split strings in C#. In the next lesson, we’ll explore control flow and conditional logic with switch statements. Let’s keep coding!

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Frequently Asked Questions

Is the “Working with Strings” lesson free?

Yes — the full text of “Working with Strings” is free to read here on the web. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the C# Academy course, upgrade to CoddyKit PRO. The C# Academy course includes 5 lessons in total.

What will I learn in “Working with Strings”?

Manipulate and process text using C#'s powerful string handling features. You practise C# Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start C# Academy?

No prior experience is required. C# Academy on CoddyKit is structured for beginners through advanced learners, so you can start here or from the beginning and move at your own pace. This is lesson 5 of 5.

How long does the “Working with Strings” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this C# Academy lesson?

Yes. Every C# Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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