Forward

Learning Go and basics of programming.

Setup

Install go: https://formulae.brew.sh/formula/go
Confirm it is installed: go version

If you see something like go version go1.XX.X <OS>/<ARCH>, you are good to go.
Run the first file: go run 00_setup/main.go

It should fail with an error message. This is expected.

Note

You can run any main.go file in this repo by running go run <path to file>

Important

Don't try setting up your editor with fancy plugins or anything yet. Just make sure you can run terminal commands and that your code is correctly highlighted. Any plugin will get in the way of learning the basics.

Exercises

Exercises are in different directories.

E.g. 00_setup contains the first exercise.

Each exercise has a main.go file that you can run with go run <path to file>.

To "solve" each exercise, look at the comments in the main.go file. You will see // TODO and a task to complete.

Once completed, you can run the file and see the output.

There will be some lines/parts marked with // IGNORE ME that you should not worry about. They are there to help with the making of the exercises, but are not relevant to the exercise itself.

Reading errors

If your code has an error, you will see an error message when running go run <path to file>. This message will help you understand what is wrong with your code.

E.g. if you run go run 00_setup/main.go without completing the exercise, you will see something like:

$ go run 00_setup/main.go
# command-line-arguments // IGNORE ME
00_setup/main.go:19:10: syntax error: unexpected name code at end of statement
^ File path             ^ Error message
                 ^ Error line
                    ^ Error column

Pay close attention to any error messages you see, as they will help you understand what is wrong with your code. If you don't understand the error message, don't worry, just ask for help.

Formatting your code

You can format your code by running go fmt <path to file>.

If you want to format all files in a directory, you can run go fmt ./....

The PR will fail if your code is not formatted correctly, so make sure to run it before submitting your work.

E.g.

In commit https://github.com/riraum/forward/commit/00bb7731ad7b4264bfdae135f475b659cb2ae4fd, I added a wrong indentation, and the lint job failed:

Error: running `go fmt ./...` results in modifications that you must check into version control:
diff --git a/00_setup/main.go b/00_setup/main.go
index bd232e6..a7f2504 100644
--- a/00_setup/main.go
+++ b/00_setup/main.go
@@ -23,3 +23,3 @@ func main() {
 	// E.g. (don't worry about the syntax yet):
-	  fmt.Println("Hello", "World!", 42, 3.14, true, false, []int{1, 2, 3})
+	fmt.Println("Hello", "World!", 42, 3.14, true, false, []int{1, 2, 3})

This means that the file 00_setup/main.go is wrongly formatted, and should be fixed.

Submitting your work

Before starting to work on a new exercise, create a new branch that will be used only for this exercise.

E.g. git checkout -b 00_setup

Make sure to commit often, ideally after each task is done.

Once you have completed the exercise, push your branch to GitHub. Then create a pull request to merge this branch and request review from nobe4. Any review/comments will be added to the pull request.

Once everything looks good and the PR has been approved, merge it, delete the branch and move on the next exercise.