What are the spread and rest operators in JavaScript?

Can you explain the spread and rest operators in JavaScript?

Sure! The spread operator (...) 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 [1, 2, 3, 4, 5].

What about the rest operator?

The rest operator also uses (...) but is used to collect multiple elements into an array. For instance, function myFunc(...args) { return args; } will gather all arguments passed to myFunc into the args array.

Can you give me an example of both in a function?

Absolutely! Here's an example: function combineArrays(...arrays) { return [].concat(...arrays); } This function uses the rest operator to take any number of arrays and combines them into one.

Are there any performance considerations when using these operators?

Yes, while they are very convenient, using them on large arrays can lead to performance issues due to the creation of new arrays. It's best to use them judiciously.