What are spread and rest parameters in JavaScript?

Can you explain what spread and rest parameters are in JavaScript?

Sure! Spread parameters allow an iterable like an array to be expanded in places where zero or more arguments are expected.

How do I use the spread operator in a function?

You can use the spread operator by placing three dots (...) before an array. For example, function myFunc(...args) {}.

What about rest parameters? How are they different?

Rest parameters also use the three dots syntax, but they collect all remaining arguments into an array. It's used in function definitions.

Can you give me an example of both in action?

Absolutely! For spread: const arr = [1, 2, 3]; const newArr = [...arr, 4, 5]; For rest: function sum(...numbers) { return numbers.reduce((a, b) => a + b, 0); }.