Class Group

code/solutions/06_2_groups.js:1–25

class Group {
  #members = [];

  add(value) {
    if (!this.has(value)) {
      this.#members.push(value);
    }
  }

  delete(value) {
    this.#members = this.#members.filter(v => v !== value);
  }

  has(value) {
    return this.#members.includes(value);
  }

  static from(collection) {
    let group = new Group;
    for (let value of collection) {
      group.add(value);
    }
    return group;
  }
}

let group = Group.from([10, 20]);
console.log(group.has(10));