Tutorials

C# String Format() Method

Posted in C# Tutorial

Updated on Nov 17, 2024

By Mari Selvan

👁️ 209 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In C# programming, the String.Format() method is a powerful tool for formatting strings by substituting placeholders with values. It belongs to the System.String class and provides a convenient way to create formatted strings.

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

💡 Syntax

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

Syntax

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public static string Format(string format, params object[] args);

format: A composite format string that contains placeholders.
args: An array of objects to format and insert into the string.

📄 Example

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

Program.cs

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using System;

class Program {
  static void Main() {
    string name = "John";
    int age = 30;

    // Format a string using placeholders
    string formattedString = string.Format("Hello, my name is {0} and I'm {1} years old.", name, age);

    // Output the formatted string
    Console.WriteLine(formattedString);
  }
}

💻 Testing the Program

The output of the above example will be:

Output

Hello, my name is John and I'm 30 years old.

🧠 How the Program Works

In this example, the Format() method is used to create a formatted string by replacing placeholders {0} and {1}> with the values of the variables name and age, respectively.

↩️ Return Value

The Format() method returns a new string that is the result of formatting the specified format string with the provided arguments.

📚 Common Use Cases

The Format() method is particularly useful when you need to create complex strings with dynamic content. It simplifies the process of concatenating values into a string, making the code more readable and maintainable.

📝 Notes

Placeholders in the format string are represented by curly braces {} with an index inside, such as {0}, {1}, etc.
The order of the values in the args array determines their placement in the formatted string.
The Format() method supports various formatting options, including alignment, precision, and format specifiers.

🎢 Optimization

The Format() method is optimized for performance, and its usage is efficient. If you have a fixed number of placeholders, consider using string interpolation ($"") in C# for improved readability.

🎉 Conclusion

The Format() method in C# is a versatile tool for creating formatted strings. It simplifies the process of string construction and enhances code readability. Understanding its usage is valuable in various scenarios, especially when dealing with dynamic content in strings.

Feel free to experiment with different format strings and explore the various formatting options provided by the Format() method. Happy coding!