Summary  
This chapter explains how to declare and manage mutable (`let`) versus immutable (`const`) variables in JavaScript and outlines best practices for clear, descriptive naming.

General domain of usage  
Game development (e.g., tracking player scores and maximum players)

Variables let you store data that can change, while constants store values that should stay the same.
Use:
- `let`: when the value can change;
- `const`: when the value should not change.

let score = 10;
score = 15; // value can change
console.log(score);

const maxPlayers = 4;
// maxPlayers = 5; // ❌ error

### Best Practices
- Use `const` by default;
- Use `let` only when needed;


## Naming Variables
Use clear and descriptive names:
```js
let playerScore = 100;
let maxLevel = 10;
```
Avoid:
- Starting with numbers;
- Reserved words;
- Unclear names like `x` or `data`.


### Why This Matters
Variables are the foundation of everything in JavaScript.
You'll use them to store user data, application state, and results.

Lær at kontrollere programlogik, strukturere data og opbygge dynamiske funktioner ved hjælp af JavaScript. Arbejd med funktioner, arrays, objekter og løkker, og anvend derefter disse færdigheder til at skabe et interaktivt profilsystem. Opnå den grundlæggende viden, der er nødvendig for at gå videre til React og moderne frontend-udvikling.

Anvend din viden i et mini-projekt, lær grundlæggende fejlfinding, og forbered dig på dine næste skridt i JavaScript.

Variabler og Konstanter

Best Practices

Naming Variables

Why This Matters