temporal-polyfill VS proposal-change-array-by-copy

Docs, Cookbook, Polyfill

Early polyfill

See https://github.com/js-temporal/temporal-polyfill for the polyfill in question.

The new change array by copy methods (ES2023) will also work with tuples. So while you can't

Change Array by Copy

Stage 3 Change array by copy proposal offers methods like sortTo() that return a new array instead of mutating the original.

Note: there's a stage 3 proposal that introduces copy = arr.toSorted().

Change Array by Copy: Provides additional methods on Array.prototype and TypedArray.prototype to enable changes on the array by returning a new copy of it with the change.

The proposal is described here, with the other methods being:

Proposal, Polyfill

You're unlikely to see any new methods being added to JavaScript's Array that would modify an array in place like reverse() and sort() do. In fact some of the new methods that are being added are versions of reverse() and sort() (and splice()) that create copies rather than modifying the originals. Read more about them here: Proposal: Change Array by copy.

Since cloning is so common, a new specification has been written which has reached stage 3, which will give us a host of new ways to copy and then change an array. This proposal is called the "Change Array by Copy" proposal. Let's take a look at how it works.