File-scoped namespaces, introduced in C# 10, provide a more concise way to declare namespaces in your code files.
This feature helps reduce nesting levels and makes your code cleaner and more readable. Let's explore how to use them effectively and understand their benefits.
Traditionally, C# developers have used block-scoped namespaces, which require curly braces and add an extra level of indentation:
namespace MyCompany.MyProduct.Features { public class UserService { private readonly string _connectionString; public UserService(string connectionString) { _connectionString = connectionString; } public void CreateUser(string username) { // Implementation } } public record User(string Username, string Email); }
With file-scoped namespaces, you can declare the namespace without braces, reducing indentation and making the code more readable:
namespace MyCompany.MyProduct.Features; public class UserService { private readonly string _connectionString; public UserService(string connectionString) { _connectionString = connectionString; } public void CreateUser(string username) { // Implementation } } public record User(string Username, string Email);
Reduced Indentation: File-scoped namespaces eliminate one level of indentation, making the code easier to read and maintain.
Single Namespace per File: File-scoped namespaces enforce a good practice of having only one namespace per file, improving code organization.
Compatibility: File-scoped namespaces work seamlessly with existing code and can be gradually adopted in your codebase.
When using file-scoped namespaces, keep these points in mind:
When converting existing code to use file-scoped namespaces:
File-scoped namespaces are a simple yet effective feature that can make your C# code more readable and maintainable. While the benefits might seem small, they add up significantly in larger codebases. Consider adopting this modern syntax in your C# projects, especially if you're using C# 10 or later.
Reading a file line by line is useful when handling large files without loading everything into memory at once.
✅ Best Practice: Use File.ReadLines() which is more memory efficient.
Example
foreach (string line in File.ReadLines("file.txt")) { Console.WriteLine(line); }
Why use ReadLines()?
Reads one line at a time, reducing overall memory usage. Ideal for large files (e.g., logs, CSVs).
Alternative: Use StreamReader (More Control)
For scenarios where you need custom processing while reading the contents of the file:
using (StreamReader reader = new StreamReader("file.txt")) { string? line; while ((line = reader.ReadLine()) != null) { Console.WriteLine(line); } }
Why use StreamReader?
Lets you handle exceptions, encoding, and buffering. Supports custom processing (e.g., search for a keyword while reading).
When to Use ReadAllLines()? If you need all lines at once, use:
string[] lines = File.ReadAllLines("file.txt");
Caution: Loads the entire file into memory—avoid for large files!
Storing passwords as plain text is dangerous. Instead, you should hash them using a strong, slow hashing algorithm like BCrypt, which includes built-in salting and resistance to brute-force attacks.
Step 1: Install BCrypt NuGet Package
Before using BCrypt, install the BCrypt.Net-Next package:
dotnet add package BCrypt.Net-Next
or via NuGet Package Manager:
Install-Package BCrypt.Net-Next
Step 2: Hash a Password
Use BCrypt.HashPassword() to securely hash a password before storing it:
using BCrypt.Net; string password = "mySecurePassword123"; string hashedPassword = BCrypt.HashPassword(password); Console.WriteLine(hashedPassword); // Output: $2a$12$...
Step 3: Verify a Password
To check a user's login attempt, use BCrypt.Verify():
bool isMatch = BCrypt.Verify("mySecurePassword123", hashedPassword); Console.WriteLine(isMatch); // Output: True
Ensuring proper hashing should be at the top of your list when it comes to building authentication systems.
In C#, you can format an integer with commas (thousands separator) using ToString with a format specifier.
int number = 1234567; string formattedNumber = number.ToString("N0"); // "1,234,567" Console.WriteLine(formattedNumber);
Explanation:
"N0": The "N" format specifier stands for Number, and "0" means no decimal places. The output depends on the culture settings, so in regions where , is the decimal separator, you might get 1.234.567.
Alternative:
You can also specify culture explicitly if you need a specific format:
using System.Globalization; int number = 1234567; string formattedNumber = number.ToString("N0", CultureInfo.InvariantCulture); Console.WriteLine(formattedNumber); // "1,234,567"
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