Bits of .NET

🛡️ Null Safety Made Easy

Null checks are verbose. Null-coalescing operators handle null elegantly. Provide defaults, chain checks, safe navigation.

📝 Null Operators

// Null-coalescing (??)
string name = user?.Name ?? "Unknown";
int age = user?.Age ?? 0;
double price = product?.Price ?? 0.0;

// Null-coalescing assignment (??=)
string name;
name ??= "Default Name"; // Only if null

// Null-conditional (?.)
string firstName = user?.Name?.FirstName; // Chain safely
int? orderCount = user?.Orders?.Count();
string street = user?.Address?.Street ?? "No address";

// Combining operators
string fullName = user?.FirstName?.ToUpper() ?? "Unknown";
string email = user?.Email?.Trim() ?? "No email";

// With nullable types
int? nullableAge = null;
int age = nullableAge ?? 25; // 25 if null

// With reference types
User? user = GetUser();
string name = user?.Name ?? "Guest";

// With Dictionaries
string value = dict?.GetValueOrDefault("key") ?? "default";

// With LINQ
var firstItem = list?.FirstOrDefault() ?? new Item();

🎯 Practical Examples

// Configuration
string apiKey = config["ApiKey"] ?? throw new Exception("ApiKey missing");
int timeout = int.Parse(config["Timeout"] ?? "30");

// Database operations
var user = await db.Users.FindAsync(id);
string displayName = user?.FullName ?? user?.Username ?? "Unknown User";

// API responses
var response = await httpClient.GetFromJsonAsync("...");
string token = response?.Data?.Token ?? "No token";

// Mapping
var dto = new UserDto
{
    Id = entity?.Id ?? 0,
    Name = entity?.Name ?? "Unknown",
    Email = entity?.Email?.ToLowerInvariant() ?? "no-email",
    CreatedAt = entity?.CreatedAt ?? DateTime.UtcNow
};

// Validation
string input = GetInput();
string sanitized = input?.Trim() ?? "";

// Event handling
string message = GetMessage() ?? "No message available";

// With arrays
string first = array?.FirstOrDefault() ?? "Empty";

// Complex chains
string result = data?.Items?.FirstOrDefault()?.Value?.ToString() ?? "No value";

✅ Benefits

• Cleaner and more concise code
• No null reference exceptions
• Safe navigation through chains
• Default values for nulls
• Improved readability