spread_operator.js

//------------------------------------------------
// COPY ELEMENTS FROM ONE ARRAY INTO ANOTHER ARRAY
//------------------------------------------------
const fruits = ['apple', 'mangoe', 'papaya'];
const updated_fruits = ['banana', ...fruits];
console.log(updated_fruits); // [ 'banana', 'apple', 'mangoe', 'papaya' ]

//-------------------
// MERGING TWO ARRAYS
//-------------------
const my_cats = ['Jimmy', 'Marty', 'Max'];
const your_cats = ['George', 'Botsoe', 'Benny'];
const our_cats = [...my_cats, ...your_cats];
console.log(our_cats); // [ 'Jimmy', 'Marty', 'Max', 'George', 'Botsoe', 'Benny' ]

//----------------
// MERGING OBJECTS
//----------------
const profile = {
  name: 'Dean Winchester',
  age: 34,
  car: 'Chevy Imala (Baby)'
}

const list_of_enemies = {
  enemy_demons: ['Abadon', 'Yellow Eyes', 'Crowley'],
  enemy_angels: ['Zacharia', 'Michael', 'Lucifer']
}

const character = {
  ...profile,
  ...list_of_enemies
}

console.log(character);
/*
  {
    name: 'Dean Winchester',
    age: 34,
    car: 'Chevy Imala (Baby)',
    enemy_demons: [ 'Abadon', 'Yellow Eyes', 'Crowley' ],
    enemy_angels: [ 'Zacharia', 'Michael', 'Lucifer' ]
  }
*/

Spread Operator Basics.