JS Data Structures presentation

Primitives

Object

Map

const map = new Map();

map.set("😂", "Cray things");
map.set("🧠", "Please use it, it's free");

map.get("🧠"); // Please use it, it's free
map.size; // 2

• Iterable
• Ordered keys
• Cool methods: get, set, has, size, delete, clear ...

WeakMap

const weak_map = new WeakMap();

const a = {
id: 1,
emotion: "😆",
};

const b = {
id: 1,
emotion: "😇",
};

weak_map.set(a, "I'm glad");
weak_map.set(b, "I'm zen. Don't worry");

weak_map.get(a); // I'm glad

• ..map
• Keys are only objects
• Keys are not enumerable, cannot use .size

Set

const set = new Set();

set.add(1);
set.add(1);
set.add(1);

set; // 0 => 1

• Unique value, all types
• Iterable
• Cool methods like map: add, has, delete, size

WeakSet

• Weak reference: not yet understand
• Set of only objects
• Not enumerable

Object