Tutorials

C# String Contains() Method

Posted in C# Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 117 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In C# programming, the string data type comes with a variety of built-in methods for efficient string manipulation.

The Contains() method is one such method that allows you to check if a specific substring is present within a given string.

In this tutorial, we'll explore the usage and functionality of the Contains() method in C#.

💡 Syntax

The syntax for the Contains() method is as follows:

Syntax

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public bool Contains(string value);

value: The substring to search for within the string.

The method returns true if the specified substring is found, and false otherwise.

📄 Example

Let's dive into an example to illustrate how the Contains() method works.

Program.cs

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using System;

class Program {
  static void Main() {
    string mainString = "C# programming is fun!";
    string searchString = "fun";

    // Check if the mainString contains the searchString
    bool containsSubstring = mainString.Contains(searchString);

    // Output the result
    Console.WriteLine($"Does the string contain '{searchString}'? {containsSubstring}");
  }
}

💻 Testing the Program

Output

Does the string contain 'fun'? True

🧠 How the Program Works

In this example, the Contains() method is used to check if the string "C# programming is fun!" contains the substring "fun" and then prints the result.

↩️ Return Value

The Contains() method returns a bool value. It is true if the specified substring is found within the string, and false otherwise.

📚 Common Use Cases

The Contains() method is particularly useful when you need to determine whether a specific sequence of characters exists within a larger string. It's commonly used for conditional logic or filtering operations based on the presence of substrings.

📝 Notes

The Contains() method is case-sensitive. If you need a case-insensitive search, consider converting both the main string and the search string to lowercase (or uppercase) using the ToLower() or ToUpper() methods before calling Contains().

🎢 Optimization

The Contains() method is optimized for performance, and no specific optimization is typically required. However, if you are performing multiple searches on the same string, consider storing the result in a variable to avoid redundant computations.

🎉 Conclusion

The Contains() method in C# is a valuable tool for string manipulation, allowing you to easily check for the presence of a substring within a string. It's a versatile method that finds application in various scenarios, from simple conditional checks to more complex filtering operations.

Feel free to experiment with different strings and substrings to explore the behavior of the Contains() method. Happy coding!