Tip: JavaScript array sorting shorthand

When sorting an array of primitive values (e.g. strings or numbers), you'll often see a lot of code that looks like this:

const arr = [8, 2, 1, 4, 5, 0];
// Sort in ascending order
arr.sort((a, b) => {
  if (a > b) return 1;
  if (b > a) return -1
  return 0;
}); // [0, 1, 2, 4, 5, 8]

While this piece of code does the job, there is also a one-line alternative for it. The trick hinges on Array.prototype.sort() expecting either a positive or a negative value to perform a swap between two elements, thus allowing for more flexible values than 1 and -1. Subtracting the numeric values in an array is sufficient and can also be used to sort the array the other way around:

const arr = [8, 2, 1, 4, 5, 0];
// Sort in ascending order
arr.sort((a, b) => a - b); // [0, 1, 2, 4, 5, 8]
// Sort in descending order
arr.sort((a, b) => b - a); // [8, 5, 4, 2, 1, 0]

If you are working with string arrays, you should instead use String.prototype.localeCompare(), as it provides far greater flexibility, by accounting for specific locales and their unique needs:

const s = ['Hi', 'Hola', 'Hello'];
// Sort in ascending order
arr.sort((a, b) => a.localeCompare(b)); // ['Hello', 'Hi', 'Hola']
// Sort in descending order
arr.sort((a, b) => b.localeCompare(a)); // ['Hola', 'Hi', 'Hello']

Do you like short, high-quality code snippets and articles? So do we! Visit 30 seconds of code for more articles like this one or follow us on Twitter for daily JavaScript, React and Python snippets! 👨‍💻