Showing how the existing abilities property isn't modified

default-property.js

const pokemon = {
  name: 'Squirtle',
  type: 'Water',
  abilities: ['Torrent', 'Rain Dish']
};

const { abilities = [], ...rest } = pokemon;
const fullSquirtle = { ...rest, abilities };

console.log(rest); //Result: { name: 'Squirtle', type: 'Water' }
//Since the pokemon object already has the abilities property, it isn't modified:
console.log({ fullSquirtle }); //Result: { name: 'Squirtle', type: 'Water', abilities: ['Torrent', 'Rain Dish'] }