30-seconds-of-code/javascript/snippets/ranking.md

title, type, tags, author, cover, dateModified

title	type	tags	author	cover	dateModified
Array ranking	snippet	array math	chalarangelo	eagle	2022-04-13T05:00:00-04:00

Calculates the ranking of an array based on a comparator function.

• Use Array.prototype.map() and Array.prototype.filter() to map each element to a rank using the provided comparator function.

const ranking = (arr, compFn) =>
  arr.map(a => arr.filter(b => compFn(a, b)).length + 1);

ranking([8, 6, 9, 5], (a, b) => a < b);
// [2, 3, 1, 4]
ranking(['c', 'a', 'b', 'd'], (a, b) => a.localeCompare(b) > 0);
// [3, 1, 2, 4]