Returns a single-dimension array with the same number of items as the receiver object. Any index with no associated item is omitted from the new array. Items in the new array will have the same order as the source array. Multi-dimension arrays arrays will be converted into a non-sparse single dimension array.
Example 5.150. Array class - makeArray method
a = .array~of("Fred", , "Mike", , "David")
b = a~makeArray -- b = .array~of("Fred", "Mike", "David")
