SWAP Statement Programming Example
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'This example uses the SWAP statement to exchange array elements that are
'out of order. The program sorts a string array in descending order using
'a shell sort.
Num% = 4
Array$(1) = "New York"
Array$(2) = "Boston"
Array$(3) = "Chicago"
Array$(4) = "Seattle"
Span% = Num% \ 2
DO WHILE Span% > 0
FOR I% = Span% TO Num% - 1
J% = I% - Span% + 1
FOR J% = (I% - Span% + 1) TO 1 STEP -Span%
IF Array$(J%) <= Array$(J% + Span%) THEN EXIT FOR
' Swap array elements that are out of order.
SWAP Array$(J%), Array$(J% + Span%)
NEXT J%
NEXT I%
Span% = Span% \ 2
LOOP
CLS
FOR I% = 1 TO Num%
PRINT Array$(I%)
NEXT I%
END