Notes — Module 0: Introduction¶

These are your personal study notes. Write freely and honestly. Incomplete notes are fine — they show where your understanding still needs work. Return to this file to add insights as they develop over time.

Module: [[modules/go-0-introduction]] Topic: [[go]] Date started: ___________ Status: Not started

Concept Map¶

Sketch how the concepts in this module relate to each other. Fill in the Mermaid diagram.

mindmap
  root((Go Introduction))
    Toolchain
      go run
      go build
      go fmt
      go vet
      go mod init
    Hello World
      package main
      import fmt
      func main
      fmt.Println
    Module System
      go.mod
      module path
      go.sum
      vs GOPATH
    Philosophy
      Simplicity
      Explicit errors
      Composition
      Fast compilation

Alternative: draw this on paper, photo it, and link the image here.

Study Tips for This Module¶

Before diving in, a few things that help with the Go introduction specifically:

Type every code example by hand. The muscle memory of package main, import "fmt", func main() matters. Don't copy-paste.
Run go fmt immediately. After writing code, run go fmt ./... and look at what it changes. This builds the habit early.
Try intentional errors. Delete the import "fmt" line and see what the compiler says. Add an unused variable. Put the { on a new line. The compiler errors are clear and educational.
Initialize a real module. Don't just run individual files — create a directory, run go mod init, and work inside that module from the start.

Key Insights¶

The "aha moments" — the things that, once understood, made the rest clear. Be specific: "I finally understood X because Y" is more useful than "X makes sense".

Add insights as you discover them
Add insights as you discover them
Add insights as you discover them

My Understanding¶

Explain the core concepts in your own words, as if teaching them to someone else. If you can't explain it simply, you don't understand it well enough yet.

package main and func main()¶

Your explanation here:

What I'm still unsure about: ___________

The go.mod module system¶

Your explanation here:

What I'm still unsure about: ___________

go run vs go build¶

Your explanation here:

What I'm still unsure about: ___________

Why unused imports are compile errors¶

Your explanation here:

Connections to Other Topics¶

How does this module connect to things you already know?

This module's concept	Connects to	How
`package main`	Python `if __name__ == "__main__":`	Both define the program entry point
`go mod init`	npm's `package.json`, pip's `requirements.txt`	Both are dependency declaration files
`go fmt`	Python's `black`, JS's `prettier`	Opinionated auto-formatters that remove style debates
Compiled binary	[[docker-containers]]	Go binaries are easy to containerize — just copy the binary

Questions That Arose¶

Log questions as they appear. Don't stop to answer them now — just capture them. Then move the serious ones to QUESTIONS.md.

Add questions here as they occur

Code Snippets Worth Remembering¶

Patterns, idioms, or examples that captured something important.

The minimal Go program¶

package main

import "fmt"

func main() {
    fmt.Println("Hello, World!")
}

Why I'm saving this: The irreducible minimum — everything Go needs to be a runnable program.

Initializing a new module¶

mkdir myproject && cd myproject
go mod init github.com/yourname/myproject

Why I'm saving this: This is always the first thing you do in a new Go project.

Checking the error pattern¶

result, err := someFunction()
if err != nil {
    return fmt.Errorf("someFunction failed: %w", err)
}

Why I'm saving this: This pattern appears in nearly every Go program. Worth internalizing from day one.

What Tripped Me Up¶

Mistakes I made, misconceptions I had, things that confused me more than they should have. Being honest here helps you later.

Add stumbling blocks here as they occur

Summary in My Own Words¶

Write a 3–5 sentence summary of this entire module without looking at any notes. If you can't do this, you need more study time.

Write your summary here after completing the module:

_Last updated: ____________