C#

If you need to print or log an object, Console.WriteLine(order) is the obvious first try, and it prints Bookstore.Order instead of the order. That’s the default ToString in C#: unless a type overrides it, it returns the type’s full name. The fix is to override ToString() in your class (or use a record), and to … Read more >>

Say you’re cleaning up an old order tracker for a Columbus coffee roaster, and it keeps daily order counts in an ArrayList. Every int that goes in gets copied into a new object on the heap, and every read needs a cast back. That’s boxing and unboxing in C#, and the tracker pays for it … Read more >>

A Phoenix freight client sent me an order import that crashed on row 7 because a dispatcher typed “N/A” in the quantity column. One bad cell killed the whole nightly run. In this tutorial, I’ll cover try catch in C# on .NET 10: the syntax, catching specific exceptions in the right order, finally, exception filters, … Read more >>

Here’s the line that takes down a sales report: totalSales / orders on a region with zero orders. With int values it throws a divide by zero exception in C#; switch both to double and it quietly prints ∞ instead. Quick answer: integer and decimal division by zero throw DivideByZeroException, so check the divisor first. … Read more >>

If you’ve written a Fee() method in a C# derived class and called it through a base-class variable, you’ve probably watched the base version run anyway, with a CS0108 warning in the build output. That’s because method overriding in C# takes two keywords: virtual on the base method and override on the derived one. Leave … Read more >>

Type casting in C# changes a value from one type to another. Widening casts like int to long happen implicitly, while narrowing casts like (int)12.97 need explicit syntax and can lose data: that one returns 12, not 13. In this tutorial, I’ll build up a little US shipping calculator and use it to show type … Read more >>

Say you’re writing the checkout for an Austin outdoor store, and method overloading in C# is how one Calculate method takes whole dollars, a price with cents, or a price plus a custom tax rate. Quick answer: declare several methods with the same name but a different number, type or order of parameters. The compiler … Read more >>

Sooner or later you’re branching on one value with five possible answers. A switch case in C# matches that value against case labels and runs the first section that fits, which reads far better than a stack of else if lines. In this tutorial, I’ll cover the switch case in C# as I use it … Read more >>

The first do while loop in C# that most people write fails before it ever runs. Look at the end of the loop: What dotnet run prints: The compiler wants a semicolon after while (tries < 3); add it and it prints 3. It’s the only C# loop that ends in ;, and it always … Read more >>

Every Monday our Dallas sales manager asks the same question: which state sold the most last week? A foreach loop in C# answers it in a few lines, because it visits every item in an array, list or dictionary without you managing an index. In this tutorial, I’ll build that sales-by-state report one step at … Read more >>