Tip 9: Avoid Sort Confusion with the Spread Operator

Sorting tabular data

You’ve seen by now that you can replace many mutating functions with the spread operator. What should you do when there’s a function that you can’t easily replace? The answer is fairly simple: Use the spread operator to create a copy of the original array, and then mutate that one.

Don’t let the simplicity of the answer fool you. Mutation bugs can sneak up when you least expect them.

This comes up in applications that have tabular sorting data. If you haven’t written an application that displays tabular data, wait around—I guarantee you’ll do it. And the minute you create that table of tabular data, the next request you’ll hear from your account or project manager is to make the table sortable.

Example: Mutation when sorting a table

Skip the UI components and look purely at the data and functions. You need to make an application that takes an array of staff members and sorts them either by name or years of service.

Start with an array of employees.