I want to create Multiton Design Pattern as part of my user module in my node.js application. And I need good examples of it.
Ok I have found answer by myself
class User {
constructor(user_id) {
console.log('constructor');
this.user_id = user_id;
}
}
const map = new Map();
const user_factory = {
get_user(user_id) {
let user = map.get(user_id);
if (user === undefined) {
user = new User(user_id);
map.set(user_id, user);
}
return user;
}
};
module.exports = user_factory;