Once you've installed, open a new command prompt and run the following command:
Once you've installed, open a new terminal and run the following command:
Command prompt
dotnet
If the installation succeeded, you should see an output similar to the following:
Command prompt
Usage: dotnet [options]Usage: dotnet [path-to-application]Options:-h|--help Display help.--info Display .NET information.--list-sdks Display the installed SDKs.--list-runtimes Display the installed runtimes.path-to-application:The path to an application .dll file to execute.
Got an error?
If you receive a 'dotnet' is not recognized as an internal or external command error, make sure you opened a new command prompt. If you can't resolve the issue, use the I ran into an issue button to get help fixing the problem.
Create your app
In your command prompt, run the following command to create your app:
In your terminal, run the following command to create your app:
Command prompt
dotnet new console -lang F# -o myFSharpApp
Then, navigate to the new directory created by the previous command:
Command prompt
cd myFSharpApp
Note: some terminals may require you to add quotes around F# like this: "F#".
The dotnet command creates a new application of type console for you. The -lang parameter specifies the F# programming language and -o creates a directory named myFSharpApp where your app is stored, and populates it with the required files. The cd myFSharpApp command puts you into the newly created app directory.
The main file in the myFSharpApp folder is Program.fs. By default, it already contains the necessary code to write "Hello World from F#!" to the Console.
Program.fs
open System[<EntryPoint>]let main argv = printfn "Hello World from F#!" 0 // return an integer exit code
Run your app
In your command prompt, run the following command:
In your terminal, run the following command:
Command prompt
dotnet run
Congratulations, you've built and run your first F# app!
Write some code
Open Program.fs in any text editor, and replace all of the code with the following. If you want to, you can replace the name Ana with your name.
Program.fs
open System// Define a new function to print a name.// It must be defined before it is called in the main function.let printGreeting name = printfn "Hello %s from F#!" name[<EntryPoint>]let main argv = // Call your new function! printGreeting "Ana" 0 // return an integer exit code
Save the Program.fs file, and run your code again.
Command prompt
dotnet run
Next steps
Now that you've got the basics, let's dig deeper into the language, with a tour of F#.
