What are the spread and rest operators in JavaScript?

Can you explain the spread operator in JavaScript?

Sure! The spread operator, represented by ..., allows you to expand an iterable (like an array) into its individual elements. For example, const arr = [1, 2, 3]; const newArr = [...arr, 4, 5]; results in newArr being [1, 2, 3, 4, 5].

What about the rest operator?

The rest operator, also represented by ..., is used to collect multiple elements into an array. For instance, in a function definition like function myFunc(...args), args will be an array containing all the arguments passed to myFunc.

Can you give me an example of both operators used together?

Absolutely! You can use both in a function like this: function combine(...args) { return [...args, 'new item']; }. If you call combine(1, 2, 3), it will return [1, 2, 3, 'new item'].

Are there any performance considerations when using these operators?

Yes, while both operators are very useful, using them with large arrays can lead to performance issues due to the creation of new arrays. It's best to use them judiciously.