问题
I want my program to output the inputted array then display the total amount I input. The total value is wrong and the value changes in the array in my program. I think my problem is the adding part. How should I fix it?
IDENTIFICATION DIVISION.
PROGRAM-ID. FOREXCHANGE.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 CURR-VAL.
02 USD PIC 999V99 VALUE 46.59.
02 AUS PIC 999V99 VALUE 32.87.
02 CND PIC 999V99 VALUE 36.37.
02 EUR PIC 999V99 VALUE 52.32.
02 YEN PIC 999V99 VALUE 0.40.
02 NZD PIC 999V99 VALUE 30.04.
02 OMN PIC 999V99 VALUE 120.99.
02 SGD PIC 999V99 VALUE 32.52.
77 AMOUNT PIC 9(6)V99.
77 NEWVAL PIC 9(4)V99.
77 ROUNDOFF PIC ZZZ,ZZ9.99.
77 VALCUR PIC 9(6)V99.
77 FORCUR PIC X(3).
77 TRANSAC PIC 9(4) OCCURS 9999 TIMES.
77 CURRENCIES PIC X(3) OCCURS 9999 TIMES.
77 AMOUNTARR PIC 9(6)V99 OCCURS 9999 TIMES.
77 AMOUNTTOT PIC 9(6)V99 OCCURS 9999 TIMES.
77 TRANSACNUM PIC 9(4) VALUE 0001.
77 CTR PIC 9(4) VALUE ZERO.
77 CTR1 PIC 9(4) VALUE ZERO.
77 CURINDEX PIC 9 VALUE 0.
77 CHOICE PIC X.
PROCEDURE DIVISION.
MAIN-MENU.
DISPLAY ERASE.
DISPLAY "MAIN MENU".
DISPLAY "1. TRANSACTION".
DISPLAY "2. UPDATE".
DISPLAY "3. SUMMARY".
DISPLAY "4. EXIT".
DISPLAY "ENTER CHOICE: " WITH NO ADVANCING.
ACCEPT CHOICE.
IF CHOICE = "1"
PERFORM ADDTRANS
ELSE IF CHOICE = "2"
PERFORM UPDATES
ELSE IF CHOICE = "3"
PERFORM SUMMARIES
ELSE IF CHOICE = "4"
STOP RUN
ELSE
DISPLAY "INVALID CHOICE! PLEASE TRY AGAIN!"
PERFORM MAIN-MENU.
SUMMARIES.
DISPLAY ERASE.
DISPLAY "SUMMARY".
DISPLAY "TRANSACTION NUMBER CURRENCY AMOUNT".
PERFORM WITH TEST AFTER VARYING CTR FROM 1 BY 1
UNTIL CTR = CURINDEX
DISPLAY " " TRANSAC(CTR) WITH NO ADVANCING
DISPLAY " " WITH NO ADVANCING
DISPLAY CURRENCIES(CTR)WITH NO ADVANCING
MOVE AMOUNTARR(CTR) TO ROUNDOFF
DISPLAY " " ROUNDOFF
END-PERFORM.
PERFORM WITH TEST AFTER VARYING CTR FROM 1 BY 1
UNTIL CTR = CURINDEX
ADD AMOUNTARR(CTR) TO AMOUNTARR(CTR)
END-PERFORM.
MOVE AMOUNTARR(CURINDEX) TO ROUNDOFF.
DISPLAY "TOTAL PHP" ROUNDOFF.
DISPLAY "GO BACK TO MAIN MENU?:[Y/N] "
WITH NO ADVANCING.
ACCEPT CHOICE.
IF CHOICE = "Y"
PERFORM MAIN-MENU
ELSE IF CHOICE = "N"
PERFORM SUMMARIES
ELSE
DISPLAY "INVALID CHOICE! GOING BACK TO MAIN MENU"
PERFORM MAIN-MENU.
ADDTRANS.
DISPLAY ERASE.
ADD 1 TO CURINDEX.
DISPLAY "TRANSACTION NUMBER: " TRANSACNUM.
MOVE TRANSACNUM TO TRANSAC(CURINDEX).
ADD 1 TO TRANSACNUM.
DISPLAY "ENTER FOREIGN CURRENCY: " WITH NO ADVANCING.
ACCEPT FORCUR.
IF FORCUR = "USD"
MOVE USD TO VALCUR
DISPLAY "ENTER AMOUNT: $" WITH NO ADVANCING
ACCEPT AMOUNT
ELSE IF FORCUR = "AUS"
MOVE AUS TO VALCUR
DISPLAY "ENTER AMOUNT: $" WITH NO ADVANCING
ACCEPT AMOUNT
ELSE IF FORCUR = "CND"
MOVE CND TO VALCUR
DISPLAY "ENTER AMOUNT: $" WITH NO ADVANCING
ACCEPT AMOUNT
ELSE IF FORCUR = "EUR"
MOVE EUR TO VALCUR
DISPLAY "ENTER AMOUNT: E" WITH NO ADVANCING
ACCEPT AMOUNT
ELSE IF FORCUR = "YEN"
MOVE YEN TO VALCUR
DISPLAY "ENTER AMOUNT: Y" WITH NO ADVANCING
ACCEPT AMOUNT
ELSE IF FORCUR = "NZD"
MOVE NZD TO VALCUR
DISPLAY "ENTER AMOUNT: $" WITH NO ADVANCING
ACCEPT AMOUNT
ELSE IF FORCUR = "OMN"
MOVE OMN TO VALCUR
DISPLAY "ENTER AMOUNT: R" WITH NO ADVANCING
ACCEPT AMOUNT
ELSE IF FORCUR = "SGD"
MOVE SGD TO VALCUR
DISPLAY "ENTER AMOUNT: $" WITH NO ADVANCING
ACCEPT AMOUNT
ELSE
DISPLAY "INVALID FOREIGN CURRENCY! PLEASE TRY AGAIN!"
SUBTRACT 1 FROM CURINDEX
SUBTRACT 1 FROM TRANSACNUM
PERFORM MAIN-MENU.
MOVE FORCUR TO CURRENCIES(CURINDEX).
MULTIPLY AMOUNT BY VALCUR GIVING AMOUNTARR(CURINDEX).
MOVE AMOUNTARR(CURINDEX) TO ROUNDOFF.
DISPLAY "PHP " ROUNDOFF.
DISPLAY "ENTER ANOTHER TRANSACTION?:[Y/N] "
WITH NO ADVANCING.
ACCEPT CHOICE.
IF CHOICE = "Y"
PERFORM ADDTRANS
ELSE IF CHOICE = "N"
PERFORM MAIN-MENU
ELSE
DISPLAY "INVALID CHOICE! GOING BACK TO MAIN MENU"
PERFORM MAIN-MENU.
UPDATES.
DISPLAY ERASE.
DISPLAY "ENTER FOREIGN CURRENCY: " WITH NO ADVANCING.
ACCEPT FORCUR.
IF FORCUR = "USD"
MOVE USD TO ROUNDOFF
DISPLAY "RECENT VALUE: " ROUNDOFF
DISPLAY "RATE: $" WITH NO ADVANCING
ACCEPT NEWVAL
MOVE NEWVAL TO USD
ELSE IF FORCUR = "AUS"
MOVE AUS TO ROUNDOFF
DISPLAY "RECENT VALUE: " ROUNDOFF
DISPLAY "RATE: $" WITH NO ADVANCING
ACCEPT NEWVAL
MOVE NEWVAL TO AUS
ELSE IF FORCUR = "CND"
MOVE CND TO ROUNDOFF
DISPLAY "RECENT VALUE: " ROUNDOFF
DISPLAY "RATE: $" WITH NO ADVANCING
ACCEPT NEWVAL
MOVE NEWVAL TO CND
ELSE IF FORCUR = "EUR"
MOVE EUR TO ROUNDOFF
DISPLAY "RECENT VALUE: " ROUNDOFF
DISPLAY "RATE: E" WITH NO ADVANCING
ACCEPT NEWVAL
MOVE NEWVAL TO EUR
ELSE IF FORCUR = "YEN"
MOVE YEN TO ROUNDOFF
DISPLAY "RECENT VALUE: " ROUNDOFF
DISPLAY "RATE: Y" WITH NO ADVANCING
ACCEPT NEWVAL
MOVE NEWVAL TO YEN
ELSE IF FORCUR = "NZD"
MOVE NZD TO ROUNDOFF
DISPLAY "RECENT VALUE: " ROUNDOFF
DISPLAY "RATE: $" WITH NO ADVANCING
ACCEPT NEWVAL
MOVE NEWVAL TO NZD
ELSE IF FORCUR = "OMN"
MOVE OMN TO ROUNDOFF
DISPLAY "RECENT VALUE: " ROUNDOFF
DISPLAY "RATE: R" WITH NO ADVANCING
ACCEPT NEWVAL
MOVE NEWVAL TO OMN
ELSE IF FORCUR = "SGD"
MOVE SGD TO ROUNDOFF
DISPLAY "RECENT VALUE: " ROUNDOFF
DISPLAY "RATE: $" WITH NO ADVANCING
ACCEPT NEWVAL
MOVE NEWVAL TO SGD
ELSE
DISPLAY "INVALID FOREIGN CURRENCY! PLEASE TRY AGAIN!"
PERFORM MAIN-MENU.
DISPLAY "--GO BACK TO MAIN MENU".
PERFORM MAIN-MENU.
UPDATE: I managed to fix the changing of the value in an array but the addition is still wrong. I found out the problem. The last value in an array adds to itself.
SUMMARIES.
DISPLAY ERASE.
DISPLAY "SUMMARY".
DISPLAY "TRANSACTION NUMBER CURRENCY AMOUNT".
PERFORM WITH TEST AFTER VARYING CTR FROM 1 BY 1
UNTIL CTR = CURINDEX
DISPLAY " " TRANSAC(CTR) WITH NO ADVANCING
DISPLAY " " WITH NO ADVANCING
DISPLAY CURRENCIES(CTR)WITH NO ADVANCING
MOVE AMOUNTARR(CTR) TO ROUNDOFF
DISPLAY " " ROUNDOFF
END-PERFORM.
PERFORM WITH TEST AFTER VARYING CTR1 FROM 1 BY 1
UNTIL CTR1 = CURINDEX
MOVE AMOUNTARR(CTR1) TO AMOUNTTOT(CTR1)
ADD AMOUNTTOT(CTR1) TO AMOUNTTOT(CTR1)
END-PERFORM.
回答1:
You can't use PERFORM how you are using it. A PERFORM cannot be in any way recursive.
Even if it could, this would be "spaghetti" code: you can't tell where you are in the program, unless you know where you came from at the time. You go from one tortuous wriggly route to another.
Another problem is that you are "falling through" all over the place. If you arrive at a paragraph from the line immediately preceding it, the paragraph will execute. This explains your apparently random additions.
The code in your program is probably about there, but you need to restructure it entirely. If you look through some of the answers to COBOL questions here, you'll see some sample code to you the general idea.
This should be something like your controlling structure:
ACCEPT CHOICE
PERFORM UNTIL CHOICE EQUAL TO "4"
IF CHOICE = "1"
PERFORM ADDTRANS
ELSE IF CHOICE = "2"
PERFORM UPDATES
ELSE IF CHOICE = "3"
PERFORM SUMMARIES
ELSE
DISPLAY "INVALID CHOICE! PLEASE TRY AGAIN!"
END-IF
END-IF
END-IF
ACCEPT CHOICE
END-PERFORM
You should change the nested-IFs to EVALUATE and you should change the tests for literal values to 88s on the field, COBOL's condition-names.
You must restructure your program. At the moment, it is unworkable, unreliable, non-portable and not of any use. However, it is only the structure (probably) that is wrong. If you get a hold on how to structure a program, and how paragraphs can be fallen-through/GO TO'd (don't do it unless you don't see a way not to, with experience there is always a way not to)/PERFORMed.
There was a recent question for which the answer was "fall-through". Have a read of that: https://stackoverflow.com/a/32885852/1927206
Remember, although the structure is wrong, the code is salvageable. It is a common mistake that COBOL beginners make, so not a big problem. Good for learning. Try to look at examples here.
来源：https://stackoverflow.com/questions/32992863/cobol-adding-an-array