IB Statements/for
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FOR statement
Syntax: FOR control-variable = start-count TO stop-count [STEP increment]
.
NEXT control-variable
Discussion: The FOR statement starts a repetitive series of program statements (i.e., a loop). The statements following a FOR statement up to the associated NEXT statement form the loop.
The control-variable parameter is a previously-defined numeric variable with sufficient length and precision to store the values specified by the start-count, stop-count, and increment parameters.
The start-count parameter is the initial value assigned to the control-variable. It may be a numeric constant or numeric variable.
The stop-count parameter is the maximum value assigned to the control-variable. Stop-count may be a numeric constant or numeric variable. When the maximum value has been reached, the statements inside the loop will be executed for a final time and program flow will continue at the statement immediately following the NEXT statement. (The control-variable will retain the maximum value assigned.)
During the looping process, the value of the control-variable is incremented according to the increment parameter. If not specified, the increment is 1. The increment may be a numeric constant or numeric variable.
FOR/NEXT loops may be nested to any level.
Example 1:
FOR VALUE = 1 TO 250 ! Start loop from 1 to 250 SQUARE = VALUE * VALUE ! Compute square PRINT (0) VALUE;SQUARE ! Print value and square NEXT VALUE ! Continue loop
Example 2:
FOR LINE = 1 TO 60 ! Loop from 1 to 60 READ (1,DATA) EXCP=9999 ! Read the next data record PRINT (2,INFO) ! Print a line on the printer NEXT LINE ! Continue loop
Example 3:
FOR I = J TO K STEP M ! Loop using variable values PRINT (0) "Value is: ";I ! Print the value NEXT I ! Continue loop
Example 4:
FOR ROW = 1 TO 50 ! Start outer loop (count 1 to 50) FOR COLUMN = 1 TO 200 ! Start inner loop (count 1 to 200) SUM=SUM+DATA(COLUMN,ROW) ! Add up array elements NEXT COLUMN ! Continue inner loop NEXT ROW ! Continue outer loop
