An array collection represents an array of data type elements,
each of which is associated with a unique key value.
Keys can have any value, string or numeric.
The %Collection.AbstractArray class provides the basic functionality of the
various array collection classes.
Set arr=##class(%ArrayOfDataTypes).%New()
; place items into the array
Do arr.SetAt("red","color")
Do arr.SetAt("large","size")
Do arr.SetAt("expensive","price")
; iterate over contents of array
Set key=""
For Set value=arr.GetNext(.key) Quit:key="" Write key,":",value,!
Finds and returns the value of the element at the location before key
in the array. If key is a null string (""), it returns
the value of the last element in the array.
The value of key, which is passed by reference, is updated to the key
value of the returned element or null string ("") if key is at the beginning of the array.
Converts the value of an incoming delimited string to a serialized state
using delim as a delimiter.
abstract method Previous(key As %String = "") as %String
Finds and returns the key value of the element at the location preceding key in the array.
If key is a null string (""), then Previous() returns the key value for the last element in the array.