Remote Processing BASIC 52 - Manual (Page 53)

RPBASIC-52 PROGRAMMING GUIDE
2-34
DO-WHILE
Syntax: D O
{program stateme nts}
WH ILE {relation al expr}
Function: Executes { program state ments} w hile {relational expr} is true .
Mode: Run
Use: 100 CLEAR TICK(0) : DO : PRINT TICK(0) : WHILE TICK(0)<10
Cards: All
D E S C R IP T I ON
The {prog ram statem ents} betw een DO and W HILE a re executed o nce, regardless of the {relational expr}
result. At WH ILE the {re lational expr} is evaluated. If true, all {program statements} are executed again,
and the test is repeated. If false, execution continues at the program statement after WHILE. DO-WHILE
and DO-UNT IL loops can be nested.
RELATED
D O - U N T IL , F O R -T O - S T E P- N E X T
EXAMPLE
The following program stays in a DO-UNTIL loop until a line has changed.
10 ON LINE 0,0,500
20 DO
30 WHILE C=0
40 PRINT "Line 0 changed. Is now a",line(0)
50 C=0
60 GOTO 20
500 C=1
510 RETURN
>run
Line 0 changed. Is now a 0
Line 0 changed. Is now a 1
Line 0 changed. Is now a 0