Literal String Handling

A guide on handling literal strings in C# code.

Project Structure

The templates folder contains a Console Application example (use latest .NET per version mapping).

templates/ └── LiteralStringSample/ ← Console Application ├── Constants/ │ ├── Messages.cs ← General message constants │ └── LogMessages.cs ← Log message constants ├── Program.cs ← Top-Level Statement entry point ├── GlobalUsings.cs └── LiteralStringSample.csproj

Rule

Literal strings should preferably be pre-defined as const string

Examples

Good Example

// Good example const string ErrorMessage = "An error has occurred.";

if (condition) throw new Exception(ErrorMessage);

Bad Example

// Bad example if (condition) throw new Exception("An error has occurred.");

Constants Class Structure

Manage by separating into static classes by message type:

// Constants/Messages.cs namespace LiteralStringSample.Constants;

public static class Messages { // Error messages public const string ErrorOccurred = "An error has occurred.";

public const string InvalidInput = "Invalid input.";

// Success messages
public const string OperationSuccess = "Operation completed successfully.";

}

// Constants/LogMessages.cs namespace LiteralStringSample.Constants;

public static class LogMessages { // Information logs public const string ApplicationStarted = "Application started.";

// Format strings
public const string UserLoggedIn = "User logged in: {0}";

}

Usage Example

using LiteralStringSample.Constants;

try { if (string.IsNullOrEmpty(input)) { throw new ArgumentException(Messages.InvalidInput); }

Console.WriteLine(Messages.OperationSuccess);

} catch (Exception) { Console.WriteLine(Messages.ErrorOccurred); }

// Using format strings Console.WriteLine(string.Format(LogMessages.UserLoggedIn, userName));

Reasons

• Maintainability: Only one place to modify when changing messages

• Reusability: Same messages can be used in multiple places

• Type safety: Typos can be caught at compile time

• Performance: Eliminates string literal duplication

• Consistency: Messages can be managed in pairs (e.g., Korean/English)