FOR

8.3

The FOR instruction allows structured looping in a PL/B program. The instruction uses the following format:

Where:

label

Optional. A Program Execution Label.

target

Required. A Numeric Variable that serves as the target for the loop.

sep

Required. A comma or one of the following prepositions: BY, TO, OF, FROM, USING, WITH, IN, or INTO.

start

Required. A Numeric Variable, literal, decimal constant or expression that is assigned to the target variable as the looping is initiated.

end

Required. A Numeric Variable, literal, decimal constant or expression that specifies the ending value of the target.

incr

Optional. A Numeric Variable, literal, constant or expression that specifies the increment value of the target variable for each iteration of the loop.

Flags Affected: NONE

Note the following:

1. The FOR statement is a program control statement that requires a REPEAT as a loop terminating statement.

2. Upon initial entry into the FOR statement loop, the {start} value is assigned to the {target} variable. Upon subsequent loops through the FOR statement the {target} value is incremented by the value of the {incr} operand.

3. If the {incr} operand is not specified, the default incrementing value is one (1).

4. The FOR loop processing starts with the {start} value and continues through the {end} value inclusively. If the {incr} value is positive, the FOR statement loop will terminate when {end} is greater than {target}. If the {incr} value is negative, the FOR statement loop will terminate when {end} is less than {target}.

5. The FILEPI count is not affected by the FOR statement execution.

6. Executing a GOTO in a FOR statement loop is not recommended. If this is done, indeterminate FOR loop program processing can be expected.

7. The FOR statement can be nested thirty-two (32) levels deep. The FOR statement is implemented as a LOOP statement operation. This means LOOP/REPEAT and FOR/REPEAT constructs combined have a limit of thirty-two nested levels.

8. The FOR statement termination can occur upon initial entry should the initial {start} and {end} values meet the termination criteria.

See Also: Example Code, Program Control Instructions