Exercise - Write your first line of F# code

2 minutes

In this exercise, we write our first line of F# code, which prints the message Hello World to the console.

Start F# Interactive

Open a command prompt
Enter the following .NET CLI command into the command prompt
```
dotnet fsi
```
When the F# Interactive terminal opens, you should see something similar to the following output:
```
Microsoft (R) F# Interactive version 11.0.0.0 for F# 5.0
Copyright (c) Microsoft Corporation. All Rights Reserved.

For help type #help;;

>
```

Write your first line of code

Add the following line of code next to the > character in the F# Interactive terminal

printfn "Hello World!";;

The code is evaluated and similar output displays on the console:

Hello World!
val it : unit = ()

Congratulations! You've written your first line of F# code!

(Optional) Write a script

Create a file called hello-world.fsx and open it in Visual Studio Code.
Add the following code to the hello-world.fsx file.
```
printfn "Hello World!"
```
Run the script using the dotnet fsi command.
```
dotnet fsi hello-world.fsx
```
Running the script produces the following output:
```
Hello World!
```

Congratulations! You wrote your first script!