Ruby Tour (17) each, collect map collect! Map!

Arr = [1, 2, 3]

1) arr2 = arr. each {| element = element * 2} # Both arr and arr2 are still equal to [1, 2, 3] each. The changes to elements in the original array traversal are not saved.
2) arr2 = arr. map {| element = element * 2} # arr is equal to [1, 2, 3] arr2 is equal to [2, 4, 6] map. The changes to the elements in the array traversal after the changes are returned are not saved.
3) arr2 = arr. map! {| Element = element * 2} # Both arr and arr2 are equal to [2, 4, 6] map! Returns the modified array traversal. Changes in the elements are saved.

Collect effect equal to map
Collect! The effect is equal to map!