inheritance.js

function Plant(name) { 
  this.name = name;
};

Plant.prototype.height = 0;

Plant.prototype.grow = function() {
  this.height += 1;
};

let plant = new Plant('hibiscus');
plant.grow();

console.log(plant); // { name: 'hibiscus', height: 1 } 

function Tree() {
  Plant.apply(this, arguments);
  this.type = 'tree';
};

Tree.prototype = Plant.prototype;

let tree = new Tree('pine');

console.log(tree); // { name: 'pine', type: 'tree' }
console.log(tree.height); // 0