To compile C# source code in a Unity Project, the Unity Editor uses a C# compiler. The C# compiler that Unity uses depends on the Scripting Runtime Version option in the Player Settings (menu: Edit > Project Settings > Player > Other Settings).
| Scripting Runtime Version | C# compiler | C# language version |
|---|---|---|
| .NET 3.5 equivalent | mcs | C# 4 |
| .NET 4.6 equivalent | Roslyn | C# 7.3 |
The Editor passes a default set of options to the C# compiler. To pass additional options in your project, see the documentation for Platform Dependent Compilation.
2018–11–07 Page published with editorial review
Roslyn compiler exposed in 2018.3 NewIn20183
C# compiler Roslyn compiler NewIn20183