What are the practical applications of ES6 WeakMap

Question

Can you tell me What are the practical applications of ES6 WeakMap?

Answer 1

Practical Applications of WeakMap:

Private Data Storage:

Store private data for objects that can't be accessed directly, ensuring data security.

const privateData = new WeakMap();

class Person {

  constructor(name) {

    privateData.set(this, { name });

  }

  getName() {

    return privateData.get(this).name;

  }

}

const person = new Person('Alice');

console.log(person.getName()); // Alice

Metadata Association:

Attach extra data (metadata) to objects without modifying them directly.

const metadata = new WeakMap();

const obj = {};

metadata.set(obj, { id: 1, info: "example" });

console.log(metadata.get(obj)); // { id: 1, info: "example" }

Event Listener Management:

Track event listeners to avoid memory leaks when elements are removed.

const listeners = new WeakMap();

const button = document.querySelector('button');

function clickHandler() {

  console.log('Clicked!');

}

listeners.set(button, clickHandler);

button.addEventListener('click', clickHandler);

Caching Results:

Cache computed results to save processing time.

const cache = new WeakMap();

function compute(obj) {

  if (cache.has(obj)) return cache.get(obj);

  const result = obj.value * 2; // Example calculation

  cache.set(obj, result);

  return result;

}