Go 101 — Fundamentals

What you’ll learn

This module covers the essential building blocks of Go from the perspective of a working TypeScript developer. Each lesson anchors a Go concept in something you already know, then shows you the Go way.

Variables — let/const → :=, zero values vs undefined
Functions — signatures, multiple returns, named returns, variadics
Control Flow — if, the one for loop that does everything, switch, range
Collections — arrays vs slices, maps (Go’s version of JS objects/Map)
Structs & Methods — value types, receivers (Go’s answer to classes)
Interfaces — implicit satisfaction (structural but explicit — like TS, but different)
Errors — errors as values, not exceptions
Packages — Go modules, exported identifiers, imports

Your first comparison

In TypeScript you probably write this every day:

const greet = (name: string): string => {
  return `Hello, ${name}!`;
};
console.log(greet("World"));

In Go the same idea looks like:

package main

import "fmt"

func greet(name string) string {
    return fmt.Sprintf("Hello, %s!", name)
}

func main() {
    fmt.Println(greet("World"))
}

A few things jump out immediately: explicit package main, no arrow functions, fmt for formatted output, and types come after parameter names. All of these will feel natural by the end of this module.

Where do types appear relative to parameter names in Go? Before the name After the name In angle brackets In a separate type block