What are the performance differences between rest and spread operators in JavaScript?

What are the performance differences between rest and spread operators in JavaScript?

The rest operator (...) is used to collect multiple elements into an array, while the spread operator (...) expands an array into individual elements. Performance can vary based on context.

Can you give me an example of each?

Sure! For the rest operator: function sum(...numbers) { return numbers.reduce((a, b) => a + b, 0); } collects all arguments into an array. For the spread operator: const arr = [1, 2, 3]; const newArr = [...arr, 4, 5]; expands arr into individual elements.

Which one is generally faster?

Generally, the performance difference is minimal for most use cases. However, the spread operator can be slightly slower when expanding large arrays due to the overhead of creating new arrays.

Are there any scenarios where one is preferred over the other?

Yes, use the rest operator when you want to gather arguments into an array, and the spread operator when you need to expand an array into individual elements.