text: let x = new Set([1, 2, 3, 4, 4, 4, 5]);
  
  x.add(6);
  x.delete(2);
  
  console.log('The set contains', x.size, 'elements.');
  console.log('The set has 1:', x.has(1));
  console.log('The set has 8:', x.has(8));
  
  //values and keys are the same in a set
  x.forEach((value, key, set) => console.log(value, key, set));
  
  //iterable
  for (let value of x) {
    console.log(value);
  }
  
  //iterable values
  for (let value of x.values()) {
    console.log(value);
  }
  
  //iterable keys
  for (let value of x.keys()) {
    console.log(value);
  }
  
  //iterable entries (key, value)
  for (let value of x.entries()) {
    console.log(value);
  }
  