Think... You have a solution with multiple C# projects and include maybe 1000 classes which are so hard to debug and test. But you have a task to validate the output of certain functions when certain parameters have specific values assigned. Especially, you don't have unit tests added or difficult to implement unit tests.  Idea... You can use C# Interactive to cater to everything above and there are many benefits. C# Interactive is a feature that comes with Visual Studio 2015 update 1 and later versions. It is a REPL Editor for C# (Read-Evaluate-Print-Loop). If you are interested in learning how to code you can use the online version of this C# Interactive to write and execute codes.  You can use Microsoft's C# learning site if you don't have Visual Studio installed on your PC.  If you have Visual Studio installed in your machine you can go to View > Other Windows > C# Interactive to open the C# Interactive window. If you want to execute any method in C# Interac...