Types in JS

types.ts

// Examples of types in JS
let count = 1;
console.log(typeof count); // number

count = "1";
console.log(typeof count); // string

count = {count: 1};
console.log(typeof count); // object

count = () => 1;
console.log(typeof count); // function

count = [1];
console.log(typeof count); // object

// Type inferrence with TS. React examples

// Start at level 1
const [level, setLevel] = useState(1);

// Overlay which shows "Game over"
const [showGameOver, setShowGameOver] = useState(false);

// The shapes, ordered by how they will appear. This is empty until "Go" is clicked
const [shapes, setShapes] = useState<Shape[]>([]);