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 >>

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 >>

Four stores, six months, one grid: that’s what our Phoenix regional manager asked for. A for loop in C# repeats code a set number of times with a counter: for (int i = 0; i < n; i++) { … }. In this tutorial, I’ll show you, one small step at a time, how the … Read more >>

Leave a file handle open in a busy service and it stays open until the garbage collector notices. C# gives you two cleanup tools, Dispose and Finalize, and they behave very differently. Quick answer: In C#, Dispose() from IDisposable releases a resource the moment you call it, usually through a using statement. Finalize is the … Read more >>

Say you’re closing out the register at a Denver bike shop, and the cashier typed an unknown number of sales before typing done. You can’t know the count up front, and that’s exactly the job of a while loop in C#: it repeats a block for as long as a condition stays true. In this … Read more >>

Need to know if a name, email or code has a certain letter in it? In C#, text.Contains(‘M’) answers that in one call and returns true or false. In this tutorial, I’ll walk one customer name, Jenna Morales, through each C# string contains character check worth knowing on .NET 10: Output: ‘M’ is in “Jenna … Read more >>

Many C# guides still teach Tuple<string, int> and a wall of Item1, Item2. It works, but it’s a heap-allocated class with names nobody can read. The modern tuple in C# is (string City, decimal Total): a light ValueTuple with real field names. In this tutorial, I’ll walk one set of store orders through every common … Read more >>

Parsing “00042” in C# gives you 42, every time. When you convert a string to int, leading zeros are dropped, because an int stores a value, not the digits you typed. In this tutorial, I’ll pin down how to convert string to int with leading zeros in C# on .NET 10: parse the number, then … Read more >>

If you need to find a value by a key, like a state capital from the code “TX”, a dictionary in C# is the answer: Dictionary<TKey, TValue> maps unique keys to values and finds any key in close to constant time. In this tutorial, I’ll use one small map of US state capitals to teach … Read more >>

Open a terminal and type dotnet –version. That’s the quickest way to check the .NET version, and it prints the SDK the CLI will use right here. dotnet –list-sdks and dotnet –list-runtimes show everything else that’s installed. In this tutorial, I’ll list the places where I check .NET version details on a real machine: the … Read more >>