SOURCE

function Person(name, age) {
  this.name = name;
  this.age = age;
}

Person.prototype.say = function() {
  console.log(this.name);
}

function Tom(name, age) {
  Person.apply(this, arguments)
}

Tom.prototype = Object.create(Person.prototype);

var tom1 = new Tom('ngnice', 10);
tom1.say();
console.log(tom1) ;
console.log(tom1 instanceof Tom);
console.log(tom1 instanceof Person);