CODEWITHSUNDEEP
javascriptclassecmascript-6
Steez
Steez

Reputation: 229

How to access Class properties outside of JavaScript Classes

How is the sound property not properly private in this JavaScript class? Additionally, how can it be accessed outside the class? I saw this in a video and attempted to access the sound property outside the class and could not.

class Dog {
  constructor() {
    this.sound = 'woof';
  }
  talk() {
    console.log(this.sound);
  }
}

Thanks!!

Upvotes: 4

Views: 4135

Answers (3)

Przemek
Przemek

Reputation: 3975

You need to create instance of your class.

class Dog {
  constructor() {
    this.sound = 'woof';
  }
  talk() {
    console.log(this.sound);
  }
}

console.log(new Dog().sound);

Upvotes: 0

Mike Cluck
Mike Cluck

Reputation: 32511

It's not private because you can access it from the outside after creating an instance of the class.

class Dog {
  constructor() {
    this.sound = 'woof';
  }
  talk() {
    console.log(this.sound);
  }
}

let dog = new Dog();
console.log(dog.sound); // <--

// To further drive the point home, check out
// what happens when we change it
dog.sound = 'Meow?';
dog.talk();

Upvotes: 7

HoofHarted
HoofHarted

Reputation: 176

You need to create an instance of the class using new. When you don't have an instance of the class, the constructor has yet to be executed, so there's no sound property yet. 

var foo = new Dog();
console.log(foo.sound);

or

This will assign a default property to the Dog class without having to create a new instance of it.

Dog.__proto__.sound = 'woof';
console.log(Dog.sound);

Upvotes: 0

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