JavaScript/TypeScript

Doesn't Array.sort output as you expected? It's because number is handled as string by default. If you want to sort the array on your needs, you need to write your own sorting logic.

Remove method doesn't exist on Array interface. So we need to implement it ourselves. This article explains how to remove elements from number/string/object array.

Isn't there an infinite loop in your code? Don't you edit an array in the loop? If so, use the copy instead.

It explains how to find the lowest missing number in an array. Not only for an array that starts with 0 but also starts with an arbitrary value. Furthermore, the step between the values can change.

By using async/await keyword with Promise, you can easily implement sleep/delay function. Furthermore, this post explains how to implement to cancel the sleep/delay for some reasons.

Symbol.iterator can be used to initialize the iterator. If you need to go back to the first element after the iterator goes forward, it's the right place to use it. This post shows the example.

keyof extracts the keys of an interface or type and can be used to generate a new type. typeof generates a type from an object. The combination of keyof and typeof can generates a type from an object.