35 replies

Constructor confusion ... JS Newbie

In codecademys JS course, a class is defined as an object blueprint, and to call it you must add the constructor function (

constructor()

constructor()

class Dog {
  constructor(name) {
    this.name = name;
    this.behavior = 0;
  }
}

class Dog {
  constructor(name) {
    this.name = name;
    this.behavior = 0;
  }
}

To create an instance, you then use the

new

new

keyword ...

const halley = new Dog('Halley');

const halley = new Dog('Halley');

But on javascript.info this is the definition of a constructor function:

function User(name) {
  this.name = name;
  this.isAdmin = false;
}

let user = new User("Jack");

function User(name) {
  this.name = name;
  this.isAdmin = false;
}

let user = new User("Jack");

... basically the class definition from codecademy, without the specific

constructor()

constructor()

syntax ...

So what is a constructor function??? Is it required to use the

constructor()

constructor()

or not??