Which Array prototype method creates a new array by transforming each element?

Which Array prototype method creates a new array by transforming each element?

• A. Filter creates a new array by transforming each element.
• B. Map creates a new array by transforming each element.
• C. Reduce reduces to a single value.
• D. Find returns the first element that passes a test.

Answer: (B)

Transforming each element and building a new array from the results is what this method does. It takes a function and calls it on every element, collecting the return values into a new array without changing the original one. For example, if you map each number to its square, [1, 2, 3].map(n => n * n) becomes [1, 4, 9]. This differs from the other array methods: filtering selects elements that pass a condition, not every element transformed; reducing combines all elements into a single value; and finding returns the first element that matches a condition, not a transformed list. So the operation that creates a new array by transforming each element is map.