Elijah-trillionz

  const getDataFromCookie = (data) => {
    const allCookies = document.cookie.split(';');
    
    const cookie = allCookies.filter((cookie) => {
      return cookie.indexOf(data) !== -1;
    });

    return cookie.length >= 1 && cookie[0].trim().split('=')[1];
  };

Elijah-trillionz

// spread operators allows any iterable to be expanded
// it can serve as a means of adding arrays (concatenation)
const arr1 = [1, 3, 4]
const arr2 = [10, 13, 5]
const bothArr = [...arr1, ...arr2]

// you can use this to update an array with
// another array without leading to a multidimensional array
let arr1 = [1, 3, 4]
const arr2 = [10, 13, 5]