Picture the shipping page of a Portland, Oregon, coffee roaster. Every bag ships in a carton, and each carton is just three numbers: length, width and height in inches. That’s the job of a struct in C#: a small value type that copies its data on assignment instead of sharing a reference. We’ll build that … Read more >>

Quick answer: C# method naming conventions say every method gets a PascalCase verb or verb phrase, like CalculateTotal, async methods end in Async, and parameters stay camelCase: I ran every rule below on .NET 10 against a gear store’s order code, then made the build flag the names you’d get wrong. What You Need Before … Read more >>

To send email with attachment in C#, build the message with MailKit’s BodyBuilder, call builder.Attachments.Add() with a file path, a byte array or a stream, and send it with MailKit’s SmtpClient. Microsoft now advises against System.Net.Mail.SmtpClient for new code. I sent every message below on .NET 10 to a local test SMTP server, so you’ll … Read more >>

The usual way to check for null in C#, if (order == null), once skipped real orders in a client’s checkout. Their Order class overloaded ==, so an empty cart compared equal to null. Quick answer: write order is null or order is not null. The compiler never calls an overloaded operator for those patterns. … Read more >>

Most field bugs we catch in code review start with name = name; inside a constructor. It compiles with a warning, and the field stays empty, because the parameter hides the field. Quick answer: the C# field naming conventions are _camelCase for private and internal fields, s_ and t_ prefixes for static and thread-static fields, … Read more >>

Most naming mistakes I fix in code reviews look like strCustName, n or tmp2. They compile, but they break the C# variable naming conventions, and the next reader has to guess what each one holds: Quick answer: name local variables and parameters in camelCase, spell words out, drop type prefixes, and save single letters for … Read more >>

To convert int to hex string with leading zeros in C#, call ToString(“X4”) and put the digit count you want after the X. Use a lowercase x for lowercase digits: That’s 255 printed as 00FF, 000000ff and 0xFF. I ran every example below on .NET 10, including the negative numbers and byte arrays that trip … Read more >>

An anonymous method in C# is a block of code with no name. You write it with the delegate keyword and assign it straight to a delegate type such as Func, Action or one you declare yourself: Anonymous methods arrived in C# 2.0, and lambdas replaced them in day-to-day code a version later. They still … Read more >>

Say you run shipping for a Columbus, Ohio, outdoor-gear store. Every order goes out by UPS ground, FedEx air or XPO freight, and each carrier prices a package its own way. That’s the job of an abstract class in C#: a base class you can’t create with new, where shared code lives once and each … Read more >>

To create a GUID in C#, call Guid.NewGuid(). It gives you a random 128-bit value in the familiar 8-4-4-4-12 hex layout, so your code can make an order ID or database key without asking a server for the next number. On .NET 9 and later you also get Guid.CreateVersion7(), which puts a timestamp up front … Read more >>