Basic programming guide, Do-until – Remote Processing BASIC for the CX-10 Modbus User Manual
Page 24
BASIC PROGRAMMING GUIDE
2-15
DO-UNTIL
Syntax:
DO
{program statements}
UNTIL relational expr
Where: relational expr is any logical evaluation such as =, <, >, etc.
Function:
Executes a number of program statements a relational expression is true.
Mode:
Run
Use:
100 A=0 : DO : A=A+1 : PRINT A : UNTIL A=4 : PRINT "Done"
DESCRIPTION
This statement always executes at least once. DO-UNTIL loops may be nested. This loop may be exited
without meeting relational expr by executing a CLEAR or CLEAR S statement.
This statement always executes to UNTIL once. When relational expr is evaluated and if it is false, program
flow branches back to DO. If true, program resumes at the next statement after UNTIL.
When there are no {program statements} between DO and UNTIL, and {relational expr} is false, the "loop"
will repeat forever, or until a
DO-UNTIL and DO-WHILE loops can be nested.
RELATED
DO-WHILE, FOR-TO-NEXT-STEP
ERROR
BAD SYNTAX
When relational expr is omitted
EXAMPLE
The following program stays in a DO-UNTIL loop until a line has changed.
10
ON LINE 0,0,500
20
DO
30
UNTIL C=1
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