Array-

Question 1

What is Array.prototype.filter useful for?

Answer 1

The filter() method creates a shallow copy of a portion of a given array, filtered down to just the elements from the given array that pass the test implemented by the provided function.

Question 2

What is Array.prototype.map useful for?

Answer 2

The map ( ) method creates a new array populated with the results of calling a provided function on every element in the calling array.