| 1: | $ SET SOURCEFORMAT"FREE" |
| 2: | IDENTIFICATION DIVISION. |
| 3: | PROGRAM-ID. PerformFormat4. |
| 4: | AUTHOR. Michael Coughlan. |
| 5: | * An example program using the PERFORM..VARYING format. |
| 6: | * Pay particular attention to the values produced by the |
| 7: | * WITH TEST BEFORE and WITH TEST AFTER loops. |
| 8: | * Note that the PERFORM within a PERFORM produces the same |
| 9: | * results as the PERFORM..VARYING..AFTER |
| 10: | |
| 11: | |
| 12: | DATA DIVISION. |
| 13: | WORKING-STORAGE SECTION. |
| 14: | 01 LoopCount PIC 9 VALUE ZEROS. |
| 15: | 01 LoopCount2 PIC S9 VALUE ZEROS. |
| 16: | |
| 17: | PROCEDURE DIVISION. |
| 18: | Begin. |
| 19: | DISPLAY "Start WHILE Iteration of LoopBody" |
| 20: | PERFORM LoopBody WITH TEST BEFORE |
| 21: | VARYING LoopCount FROM 1 BY 2 |
| 22: | UNTIL LoopCount GREATER THAN 5. |
| 23: | DISPLAY "Finished WHILE iteration. LoopCount = " LoopCount. |
| 24: | |
| 25: | DISPLAY "Start REPEAT Iteration of LoopBody" |
| 26: | PERFORM LoopBody WITH TEST AFTER |
| 27: | VARYING LoopCount FROM 1 BY 2 |
| 28: | UNTIL LoopCount GREATER THAN 5. |
| 29: | DISPLAY "Finished REPEAT iteration. LoopCount = " LoopCount. |
| 30: | |
| 31: | DISPLAY "Start inline loops" |
| 32: | PERFORM VARYING LoopCount FROM 1 BY 1 |
| 33: | UNTIL LoopCount GREATER THAN 4 |
| 34: | PERFORM VARYING LoopCount2 FROM 5 BY -2 |
| 35: | UNTIL LoopCount2 LESS THAN ZERO |
| 36: | DISPLAY "InLine loop " WITH NO ADVANCING |
| 37: | DISPLAY "LoopCount = " LoopCount " LoopCount2 = " LoopCount2 |
| 38: | END-PERFORM |
| 39: | END-PERFORM. |
| 40: | DISPLAY "Finished inline loops". |
| 41: | |
| 42: | DISPLAY "Start PERFORM VARYING..AFTER". |
| 43: | PERFORM LoopBody VARYING LoopCount FROM 1 BY 1 |
| 44: | UNTIL LoopCount GREATER THAN 4 |
| 45: | AFTER LoopCount2 FROM 5 BY -2 |
| 46: | UNTIL LoopCount2 LESS THAN ZERO. |
| 47: | DISPLAY "Finished PERFORM VARYING..AFTER". |
| 48: | STOP RUN. |
| 49: | |
| 50: | |
| 51: | LoopBody. |
| 52: | DISPLAY "LoopBody " WITH NO ADVANCING |
| 53: | DISPLAY "LoopCount = " LoopCount " LoopCount2 = " LoopCount2. |