Use C# interactive in Visual Studio to experiment with your code on the fly
I needed to quickly test a regular expression, and the new feature of Visual Studio 2015 came to the rescue: C# Interactive
You will find this under View → Other Windows → C# Interactive
In my case I wanted to test how the Regex.IsMatch() method handled strings that were null or empty. Note that I had to import .NET's RegularExpressions library.
> string href = null; > using System.Text.RegularExpressions; > Regex.IsMatch(href, @"^http://") System.ArgumentNullException: Value cannot be null > href = ""; > Regex.IsMatch(href, @"^http://") false > href = "http://www.test.com"; > Regex.IsMatch(href, @"^http://") true