Tree & its Node using ES6 Classes in javascript.

tree.js

class Node {
  constructor(data) {
    this.data = data;
    this.children = [];
  }
  add(data) {
    this.children.push(new Node(data));
  }
  remove(data) {
    this.children = this.children.filter(child => child.data !== data);
  }
}
class Tree {
  constructor() {
    this.root = null;
  }
}
const t = new Tree();
t.root = new Node('a');
t.root.add('b');
t.root.add('c');