ECMAScript Cookbook

How to do it...

1. Open your command-line application, and navigate to your workspace.
2. Create a new folder named 12-04-create-weak-set-from-data.
3. Create a main.js file that defines a new class named Rocket that takes a constructor argument name and assigns it to an instance property:

// main.js 
class Rocket { 
  constructor(name) { 
    this.name = name; 
  } 
}    

4. Create a main function with an array of rocket instances. Create a new WeakSet from the array. Try to add a string to WeakSet:

// main.js 
export function main() { 
  const rockets = [ 
    new Rocket('US: Saturn V'), 
    new Rocket('US: Saturn V'), 
    new Rocket('US: Saturn V'), 
    new Rocket('USSR: Soyuz') , 
    new Rocket('CN: Long March') 
  ] 
 
  const rocketSet = new WeakSet(rockets); 
  console.log(rockets);
}  

5. Start ...