Getting Started

Contents

1. Install the .NET Core SDK
2. “Hello World!”
3. Restore Dependencies
4. Run it!

## Install the .NET Core SDK

Install the .NET Core SDK preview1 from http://dot.net.

You can install from packages or from binaries. If you install from binaries, just unzip and add the directory to PATH

After you install the tools, check if the .NET SDK works, by running:

dotnet --info

The expected output (and exit code zero) is:

.NET Command Line Tools (1.0.0-preview1-002702)

Product Information:
 Version:     1.0.0-preview1-002702
 Commit Sha:  6cde21225e

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.10586
 OS Platform: Windows
 RID:         win10-x64

## Hello World!

The simplest way to create a new F# console app for .NET Core is to use the dotnet new command.

NOTE The mkdir and cd are needed because dotnet new creates the project in the current directory.

mkdir helloworld
cd helloworld
dotnet new --lang f#

If everything is okay, you should see:

Created new F# project in c:\helloworld.

The dotnet new --lang f# command creates the following in the current directory:

• Program.fs the F# source file with main
• project.json the project file
• NuGet.Config list of Nuget feeds.

## Restore Dependencies

The project depends on the .NET Standard Library and FSharp.Core library. Before you can run the app, you need to restore all of the project's dependencies.

To download these dependencies, run:

dotnet restore

The expected output is:

log  : Restoring packages for c:\helloworld\project.json...
info :   GET https://dotnet.myget.org/F/dotnet-core/api/v3/flatcontainer/microsoft.netcore.platforms/index.json
...
verbose nuget
...
info :   NotFound https://www.myget.org/F/fsharp-daily/api/v3/flatcontainer/microsoft.netcore.platforms/index.json 108ms
info : Committing restore...
log  : Restore completed in 34962ms.
NuGet Config files used:
    c:\helloworld\NuGet.Config
    C:\Users\user\AppData\Roaming\NuGet\NuGet.Config
Feeds used:
    https://dotnet.myget.org/F/dotnet-cli/api/v3/index.json
    https://api.nuget.org/v3/index.json
    https://www.myget.org/F/fsharp-daily/api/v3/index.json

This command will create in the project directory:

• project.lock.json

The project.lock.json contains the list of all packages/version needed by the project Think about it as an build temp file

## Run it!

To build and run the console app, use the dotnet run command. The dotnet run command builds the project, and if successful, runs it with the command line arguments passed to dotnet run.

dotnet run arg1 arg2

If everything it's okay, the output should be:

Compiling helloworld (.NETStandard,Version=v1.5) will be compiled because expected outputs are missing

Compilation succeeded.
    0 Warning(s)
    0 Error(s)

Time elapsed 00:00:07.1147471


Hello World!
[|"arg1"; "arg2"|]

The first part is the build output. The second part the console app execution output.