Class

There is a live demo from GoogleChrome

about constructor, super.etc

Example

ES6

class User {
  constructor(firstName, lastName) {
    this.firstName = firstName
    this.lastName = lastName
  }

  fullName() {  //  function
    return `${this.firstName} ${this.lastName}`
  }
}

let user = new User('David', 'Chen')
user.fullName()  // David Chen

equal to ES5:

function User(firstName, lastName) {
  this.firstName = firstName
  this.lastName = lastName
}

User.prototype.fullName = function() {
  return '' + this.firstName + this.lastName
}