Now when adding new items you have to be careful about which index you’re adding. Otherwise you’ll create a sparse array, which is an array with “holes” in it (like an array with values at 0 and 2, but no value at 1). Having a sparse array isn’t necessarily a bad thing, but it does require special attention. For now, there’s another way to add new items without worrying about the index, and that’s
push. Here’s how it works:
how to add items to an array without worrying about which index is available next?