TeleFlow BasicScript DoWhileLoop

From TeleFlow

Executes one or more statements in the loop created by DO … LOOP until certain conditions are met as described by the WHILE or UNTIL statement or until an EXIT DO is reached.

Syntax

DO
EXIT DO
LOOP

DO WHILE condition
       [EXIT DO]
LOOP

DO UNTIL condition
       [EXIT DO]
LOOP

DO
       [EXIT DO]
LOOP WHILE condition

DO
       [EXIT DO]
LOOP UNTIL condition

condition: a BasicScript statement that results in a numeric value. condition is said to succeed if the value is not zero and to fail if the value is zero. The WHILE BasicScript keyword will continue a DO loop until condition fails (value is zero). The UNTIL BasicScript keyword will continue a DO loop until a condition succeeds (value is not zero). If the WHILE or UNTIL keyword is found after the DO, condition is evaluated prior to the entry of the DO loop (meaning that there may be no execution of the content of the DO loop based on the result of condition). If the WHILE or UNTIL keyword is found after the LOOP, condition is evaluated only after the first loop. The WHILE and UNTIL keywords are optional and exclusive. If the DO loop does not contain a WHILE and UNTIL keyword, the EXIT DO is expected to escape the DO loop, otherwise the execution of the code would result in an infinite loop. Note that the syntax of EXIT WHILE and EXIT UNTIL are equivalent to EXIT DO to promote code readability.

Related Steps

BasicScript

Examples

BasicScript code	Result
PRINT "start"	start
@A = 1	1
DO	2
PRINT("@A")	3
@A = @A + 1	4
LOOP UNTIL (@A>=5)	5
PRINT "end"	end
PRINT "start"	start
@A = 10	10
DO PRINT("@A")	end
@A = @A + 1
LOOP WHILE (@A<=5)
PRINT "end"
PRINT "start"	start
@A = 1	1
DO UNTIL (@A>=5)	2
PRINT("@A")	3
@A = @A + 1	4
LOOP	end
PRINT "end"
PRINT "start"	start
@A = 1	1
DO WHILE (@A<=5)	2
PRINT("@A")	3
@A = @A + 1	4
LOOP	5
PRINT "end"	end
PRINT "start"
@A = 10	start
DO WHILE (@A<=5)	end
PRINT("@A")
@A = @A + 1
LOOP
PRINT "end"
PRINT "start"
@A = 10	start
DO WHILE (@A>=5)	end
PRINT("@A")
@A = @A + 1
LOOP
PRINT "end"
PRINT "start"
@A = 1	start
DO	1
PRINT("@A")	2
@A = @A + 1	3
IF @A >= 5 THEN	4
EXIT DO	5
END	end
LOOP
PRINT "end"