DO...LOOP
(Statement)
Repeat a block of statements while a condition is True or until a condition becomes True.
DO [{WHILE|UNTIL}[<conditional expression>]]
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LOOP
Or
DO
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LOOP [{WHILE|UNTIL}[<conditional expression>]]
DO WHILE and DO UNTIL are pretest loops.
LOOP WHILE and LOOP UNTIL are posttest loops.
A WHILE statement executes repeatedly while a condition is true (not 0), an UNTIL statement, until a condition becomes true.
In the expression specified by <conditional expression>, if the right-hand side is omitted, the system evaluates whether or not the value is true (not 0).
If <conditional expression> is omitted, the condition will be assumed as true (not 0). As a result, the WHILE statement falls into an infinite loop. An UNTIL never executes in a pretest loop and it executes only once in a posttest loop.
Although there is also a WHILE...WEND statement that is functionally equivalent to the DO WHILE...LOOP statement, using only DO WHILE...LOOP is recommended.
Although there is also a REPEAT...UNTIL statement that is functionally equivalent to the DO...LOOP UNTIL statement, using only DO...LOOP UNTIL is recommended.
WHILE and UNTIL can be omitted, but the loop becomes infinite.
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DEFINT li1, li2, li3, li4, li5, li6, li7, li8, li9
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DO WHILE li1 > li2
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'Repeat in a pretest loop
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IF li1 = 4 THEN EXIT DO
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'If li1=4, exit from DO...LOOP
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FOR li3 = 0 TO 5
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'Repeat the process of FOR...NEXT 5 times
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FOR li4 = li5 TO li6
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'Repeat the process of FOR...NEXT while adding 1 to the
'value of li5 each time the process is done until li5
'becomes the value of li6
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FOR li7 = 1 TO li8 STEP 2
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'Repeat the process of FOR...NEXT while adding 2 to the
'value starting with 1 each time the process is done
'until the value becomes li8
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IF li2 = 2 THEN EXIT FOR
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'If li2=2, exit from FOR...NEXT
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DO WHILE li2 < li9
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'Repeat in a pretest loop
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GOSUB *samp2
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li9 = li9 + 1
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LOOP
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'Call a GOSUB *samp2 statement while li2 < li9
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NEXT li7
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'Repeat
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NEXT
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'Repeat
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NEXT
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'Repeat
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li9 = 0
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DO
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'Repeat in a posttest loop
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GOSUB *samp2
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li9 = li9 + 1
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LOOP UNTIL li9 < 5
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'Call a GOSUB *samp2 statement until li9 < 5
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LOOP
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'Repeat
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