1.0 Behavior with Holes in Array
The following tests ensure that map skips holes in the array it constructs. You should see false and true printed in that order, followed by the printing of the indexes and values in two arrays, the first of which has no indexes and the second of which has one, whose value is NaN:

false
true
The following indexes are in the result array:
End indexes in the result array.
The following indexes are in the result array:
15: NaN
End indexes in the result array.