Basic Characteristics RAPID

Example
FOR i FROM 10 TO 2 STEP -1 DO
a{i} := a{i-1};
ENDFOR
Program execution
Limitations
Syntax
The values in an array are adjusted upwards so that a{10}:=a{9}, a{9}:=a{8} etc.
1. The expressions for the start, end and step values are calculated.
2. The loop counter is assigned the start value.
3. The value of the loop counter is checked to see whether its value lies between the
start and end value, or whether it is equal to the start or end value. If the value of the
loop counter is outside of this range, the FOR loop stops and program execution continues
with the instruction following ENDFOR.
4. The instructions in the FOR loop are executed.
5. The loop counter is incremented (or decremented) in accordance with the step value.
6. The FOR loop is repeated, starting from point 3.
The loop counter (of data type num) can only be accessed from within the FOR loop
and consequently hides other data and routines that have the same name. It can only be
read (not updated) by the instructions in the FOR loop.
Decimal values for start, end or stop values, in combination with exact termination conditions
for the FOR loop, cannot be used (undefined whether or not the last loop is running).
(EBNF)
FOR FROM TO
[ STEP ] DO
ENDFOR
::=
8-FOR-2 RAPID Reference Manual