I was asked this question during my “Language Preview Session in Microsoft Reboot Camp”, last week. Sharing the same answer over here for all of you. While we create project in Visual Studio, we generally select / view the targeted version of Framework in the “New Project” Dialog window. How do we know what is the current language version it is using? So for an example, if you are running on Visual Studio 2015, and create a c# project with latest .NET Framework, your language version should be defaulted to “C# 6.0”.
This is how you can check and you can find list of all supported version as well.
Right Click on the Project, Select –> Properties from the context menu.
Navigate to Build Tab, and select “Advanced” button.
This will bring “Advanced Build Settings” windows, where you can check the dropdown option for “Language Version”.