30-seconds-of-code/snippets/orderWith.md

title, tags, firstSeen, lastUpdated

title	tags	firstSeen	lastUpdated
orderWith	array,object,intermediate	2020-10-04T12:11:10+03:00	2020-10-21T21:54:53+03:00

Sorts an array of objects, ordered by a property, based on the array of orders provided.

• Use Array.prototype.reduce() to create an object from the order array with the values as keys and their original index as the value.
• Use Array.prototype.sort() to sort the given array, skipping elements for which prop is empty or not in the order array.

const orderWith = (arr, prop, order) => {
  const orderValues = order.reduce((acc, v, i) => {
    acc[v] = i;
    return acc;
  }, {});
  return [...arr].sort((a, b) => {
    if (orderValues[a[prop]] === undefined) return 1;
    if (orderValues[b[prop]] === undefined) return -1;
    return orderValues[a[prop]] - orderValues[b[prop]];
  });
};

const users = [
  { name: 'fred', language: 'Javascript' },
  { name: 'barney', language: 'TypeScript' },
  { name: 'frannie', language: 'Javascript' },
  { name: 'anna', language: 'Java' },
  { name: 'jimmy' },
  { name: 'nicky', language: 'Python' },
];
orderWith(users, 'language', ['Javascript', 'TypeScript', 'Java']);
/* 
[
  { name: 'fred', language: 'Javascript' },
  { name: 'frannie', language: 'Javascript' },
  { name: 'barney', language: 'TypeScript' },
  { name: 'anna', language: 'Java' },
  { name: 'jimmy' },
  { name: 'nicky', language: 'Python' }
]
*/