Rest parameters

Treats arguments as an array

function foo(...bar) {
  console.log(bar.join(' ')); // Logs 'I can haz teh arguments'
}
foo('I', 'can', 'haz', 'teh', 'arguments');

rules

1. It is like arguments but the rest parameters is a real array.
2. You just can have one rest parameter per function and has to be in the last position.
3. You can't use arguments