ES2019 Added Class Private Access Modifier

ES2016 had introduced class without the access modified. Refer to my below article. 

https://scalaoncloud.blogspot.com/2016/12/javascript-evolution-esmascript-6.html

ES2019 has new Class Access Modified. You can add a private modified with # infont. For example:

class SponsorWidget {

  constructor(name, description, url) {

    this.name = name;

    this.description = description;

    this.url = url;

  }

  // Private method

  #buildURL(url) {

    console.log(url);

  }

  render() {

    // Calling private method

    this.#buildURL(this.url);

  }

}

// Here is how we involve the class

let sponsorWidget = new SponsorWidget(

  "Google",

  "Search",

  "https://www.google.com"

);

sponsorWidget.render();

// Error throw.

sponsorWidget.#buildURL("https://www.hotmail.com");