free online c# editor code example
Example: c# online compiler
These two are goods C# compilers:
https://repl.it/languages/csharp
https://www.tutorialspoint.com/compile_csharp_online.php
These two are goods C# compilers:
https://repl.it/languages/csharp
https://www.tutorialspoint.com/compile_csharp_online.php