科波，找到一个百分比

Question

我正在为我的班里做一项作业，我很难得到一个百分比来显示我的COBOL实验室的正确价值。

我的问题是贴现率/WS-%-折扣(至少，我相信是这样)。

当程序运行时，我得到了结果50.0。我应该得到的结果是55.6。我不太确定我哪里出了问题。

这是我目前为程序编写的代码。

  *
   IDENTIFICATION DIVISION.
   PROGRAM-ID. LAB2.
   AUTHOR. XXXXXXX XXXXXXXXXXX.

  *
   ENVIRONMENT DIVISION.
   INPUT-OUTPUT SECTION.
   FILE-CONTROL.

       SELECT IPT-FILE ASSIGN TO 'LAB2.DAT'
           ORGANIZATION IS LINE SEQUENTIAL.

       SELECT PRT-FILE ASSIGN TO 'LAB2_OUTPUT.DAT'
           ORGANIZATION IS LINE SEQUENTIAL.

  *
   DATA DIVISION.
   FILE SECTION.

  *
   FD IPT-FILE
       RECORD CONTAINS 80 CHARACTERS
       RECORDING MODE IS F
       DATA RECORD IS INPUT-RECORD.

   01 IPT-RECORD.
       05 IPT-INV-NUMBER       PIC 9(04).
       05 IPT-INV-QUANTITY     PIC 9(03).
       05 IPT-INV-DESCRIPTION  PIC X(13).
       05 IPT-INV-UNITPRICE    PIC 9999V99.
       05 IPT-INV-PROD-CLASS   PIC 9(01).

  *
   FD PRT-FILE
       RECORD CONTAINS 132 CHARACTERS
       RECORDING MODE IS F
       DATA RECORD IS PRT-LINE.

   01 PRT-LINE.
       05 FILLER               PIC X(04).
       05 PRT-INV-NUMBER       PIC 9(04).
       05 FILLER               PIC X(02).
       05 PRT-EXTENDED-PRICE   PIC Z,ZZZ,ZZ9.99.
       05 FILLER               PIC X(04).
       05 PRT-DISCOUNT-AMOUNT  PIC ZZZ,ZZ9.99.
       05 FILLER               PIC X(03).
       05 PRT-NET-PRICE        PIC Z,ZZZ,ZZ9.99.
       05 FILLER               PIC X(10).
       05 PRT-PRODUCT-CLASS    PIC 9.
       05 FILLER               PIC X(07).
       05 PRT-TRANS-PERCENT    PIC Z9.9.
       05 FILLER               PIC X(05).
       05 PRT-TRANS-CHARGE     PIC ZZZ,ZZ9.99.

  *
   WORKING-STORAGE SECTION.
  *
   01 EOF-SWITCH               PIC X VALUE 'N'.

  *
   01 WS-EXTENDED-COST         PIC 9(07)V99.

   01 WS-DISCOUNT-AMOUNT       PIC 9(06)V99.

   01 WS-NET-COST              PIC 9(07)V99.

   01 WS-TRANS-PERCENT         PIC ZZ9V9.

   01 WS-TRANS-COST            PIC 9(06)V99.

  *
   01 WS-TOTAL-EXTENDED-COST   PIC 9(09)V99 VALUE ZERO.

   01 WS-TOTAL-NET-COST        PIC 9(08)V99 VALUE ZERO.

   01 WS-TOTAL-TRANS-COST      PIC 9(08)V99 VALUE ZERO.

   01 WS-TOTAL-WITH-DISCOUNT   PIC 99V9 VALUE ZERO.

   01 WS-TOTAL-ITEMS           PIC 99V9 VALUE ZERO.

   01 WS-PERCENT-WITH-DISCOUNT PIC 99V9.

   01 WS-TOTAL-NO-DISCOUNT     PIC 99V9 VALUE ZERO.

  *
   01 HEADING-NAME.
       05 MY-NAME              PIC X(20) VALUE
           'XXXXX XXXXXXX, LAB 2'.

   01 HEADING-COLUMN-1.
       05 FILLER               PIC X(05) VALUE SPACES.
       05 COLUMN-1-INV-NUM     PIC X(03) VALUE 'INV'.
       05 FILLER               PIC X(06) VALUE SPACES.
       05 COLUMN-1-EXT-PRC     PIC X(08) VALUE 'EXTENDED'.
       05 FILLER               PIC X(06) VALUE SPACES.
       05 COLUMN-1-DISC-AMT    PIC X(08) VALUE 'DISCOUNT'.
       05 FILLER               PIC X(06) VALUE SPACES.
       05 COLUMN-1-NET-PRC     PIC X(09) VALUE 'NET PRICE'.
       05 FILLER               PIC X(06) VALUE SPACES.
       05 COLUMN-1-CLASS       PIC X(05) VALUE 'CLASS'.
       05 FILLER               PIC X(06) VALUE SPACES.
       05 COLUMN-1-TRANS-P     PIC X(05) VALUE 'TRANS'.
       05 FILLER               PIC X(06) VALUE SPACES.
       05 COLUMN-1-TRANS-C     PIC X(14) VALUE 'TRANSPORTATION'.

   01 HEADING-COLUMN-2.
       05 FILLER               PIC X(05) VALUE SPACES.
       05 COLUMN-2-INV-NUM     PIC X(03) VALUE 'NUM'.
       05 FILLER               PIC X(09) VALUE SPACES.
       05 COLUMN-2-EXT-PRC     PIC X(08) VALUE 'PRICE'.
       05 FILLER               PIC X(05) VALUE SPACES.
       05 COLUMN-2-DISC-AMT    PIC X(08) VALUE 'AMOUNT'.
       05 FILLER               PIC X(06) VALUE SPACES.
       05 COLUMN-2-NET-PRC     PIC X(09) VALUE SPACES.
       05 FILLER               PIC X(06) VALUE SPACES.
       05 COLUMN-2-CLASS       PIC X(05) VALUE SPACES.
       05 FILLER               PIC X(08) VALUE SPACES.
       05 COLUMN-2-TRANS-P     PIC X(05) VALUE '%'.
       05 FILLER               PIC X(05) VALUE SPACES.
       05 COLUMN-2-TRANS-C     PIC X(14) VALUE 'CHARGE'.

   01 BLANK-LINE.
       05  BLANK-SPACE         PIC X VALUE SPACES.

   01 TOTAL-FOOTER.
       05 FILLER               PIC X(07) VALUE SPACES.
       05 TOTAL-EXTENDED-COST  PIC $$$$,$$$,$$9.99.
       05 FILLER               PIC X(15) VALUE SPACES.
       05 TOTAL-NET-COST       PIC $$$,$$$,$$9.99.
       05 FILLER               PIC X(23) VALUE SPACES.
       05 TOTAL-TRANS-COST     PIC $$$,$$$,$$9.99.

   01 TOTAL-NO-DISCOUNT-FOOTER.
       05 TOTAL-SENTENCE       PIC X(31) VALUE
           'TOTAL ITEMS WITHOUT DISCOUNT = '.
       05 TOTAL-NO-DISCOUNT    PIC Z9.

   01 PERCENT-DISCOUNT-FOOTER.
       05 PERCENT-SENTENCE     PIC X(44) VALUE
           'PERCENT OF ITEMS THAT RECEIVED A DISCOUNT = '.
       05 PERCENT-DISCOUNT     PIC Z9.9.

  *
   PROCEDURE DIVISION.
  *
       OPEN INPUT IPT-FILE.
       OPEN OUTPUT PRT-FILE.

  *
       WRITE PRT-LINE FROM HEADING-NAME AFTER ADVANCING 0 LINES.
       WRITE PRT-LINE FROM HEADING-COLUMN-1 AFTER ADVANCING 3 LINES.
       WRITE PRT-LINE FROM HEADING-COLUMN-2 AFTER ADVANCING 1 LINES.
       WRITE PRT-LINE FROM BLANK-LINE AFTER ADVANCING 1 LINES.

  *
       READ IPT-FILE AT END MOVE 'Y' TO EOF-SWITCH.

  *
       PERFORM MAIN-LOOP UNTIL EOF-SWITCH EQUALS 'Y'.

  *
       DIVIDE WS-TOTAL-WITH-DISCOUNT BY WS-TOTAL-ITEMS
           GIVING WS-PERCENT-WITH-DISCOUNT.

       MULTIPLY WS-PERCENT-WITH-DISCOUNT BY 100
           GIVING WS-PERCENT-WITH-DISCOUNT.

  *
       MOVE WS-TOTAL-EXTENDED-COST TO TOTAL-EXTENDED-COST.
       MOVE WS-TOTAL-NET-COST TO TOTAL-NET-COST.
       MOVE WS-TOTAL-TRANS-COST TO TOTAL-TRANS-COST.
       MOVE WS-TOTAL-NO-DISCOUNT TO TOTAL-NO-DISCOUNT.
       MOVE WS-PERCENT-WITH-DISCOUNT TO PERCENT-DISCOUNT.

  *
       WRITE PRT-LINE FROM TOTAL-FOOTER AFTER ADVANCING 3 LINES.
       WRITE PRT-LINE FROM TOTAL-NO-DISCOUNT-FOOTER AFTER
           ADVANCING 3 LINES.
       WRITE PRT-LINE FROM BLANK-LINE AFTER ADVANCING 1 LINES.
       WRITE PRT-LINE FROM PERCENT-DISCOUNT-FOOTER AFTER ADVANCING
           1 LINES.

  *
       CLOSE IPT-FILE, PRT-FILE.
       STOP RUN.

  *
   MAIN-LOOP.

       MOVE SPACES TO PRT-LINE.

  *
       MULTIPLY IPT-INV-QUANTITY BY IPT-INV-UNITPRICE
           GIVING WS-EXTENDED-COST ROUNDED.
       MOVE WS-EXTENDED-COST TO PRT-EXTENDED-PRICE.

  *
       ADD 1 TO WS-TOTAL-ITEMS

  *
       IF WS-EXTENDED-COST IS GREATER THAN 200 THEN
           MULTIPLY WS-EXTENDED-COST BY 0.11 GIVING
               WS-DISCOUNT-AMOUNT ROUNDED

           ADD 1 TO WS-TOTAL-WITH-DISCOUNT
  *
       ELSE
           MOVE ZERO TO WS-DISCOUNT-AMOUNT

           ADD 1 TO WS-TOTAL-NO-DISCOUNT

       END-IF.

  *
       IF IPT-INV-PROD-CLASS IS EQUAL TO 1 THEN
           MOVE 27.0 TO WS-TRANS-PERCENT

           MULTIPLY WS-EXTENDED-COST BY 0.27 GIVING
               WS-TRANS-COST ROUNDED
  *
       ELSE IF IPT-INV-PROD-CLASS IS EQUAL TO 2 THEN
           MOVE 17.0 TO WS-TRANS-PERCENT

           MULTIPLY WS-EXTENDED-COST BY 0.17 GIVING
               WS-TRANS-COST ROUNDED
  *
       ELSE IF IPT-INV-QUANTITY IS GREATER THAN 100 THEN
           MOVE 13.5 TO WS-TRANS-PERCENT

           MULTIPLY WS-EXTENDED-COST BY 0.135 GIVING
               WS-TRANS-COST ROUNDED
  *
       ELSE
           MOVE ZERO TO WS-TRANS-PERCENT
           MOVE 25.00 TO WS-TRANS-COST

       END-IF.

  *
       SUBTRACT WS-EXTENDED-COST FROM WS-DISCOUNT-AMOUNT
           GIVING WS-NET-COST.

       ADD WS-EXTENDED-COST TO WS-TOTAL-EXTENDED-COST.
       ADD WS-NET-COST TO WS-TOTAL-NET-COST.
       ADD WS-TRANS-COST TO WS-TOTAL-TRANS-COST.


  *
       MOVE IPT-INV-NUMBER TO PRT-INV-NUMBER.
       MOVE WS-EXTENDED-COST TO PRT-EXTENDED-PRICE.
       MOVE WS-DISCOUNT-AMOUNT TO PRT-DISCOUNT-AMOUNT.
       MOVE WS-NET-COST TO PRT-NET-PRICE.
       MOVE IPT-INV-PROD-CLASS TO PRT-PRODUCT-CLASS.
       MOVE WS-TRANS-PERCENT TO PRT-TRANS-PERCENT.
       MOVE WS-TRANS-COST TO PRT-TRANS-CHARGE.

  *
       WRITE PRT-LINE AFTER ADVANCING 1 LINES.

  *
       READ IPT-FILE AT END MOVE 'Y' TO EOF-SWITCH.

以下是.dat文件所保存的信息。

2047105TYPEWRITER   0800002
1742010HANDLE       0010001
2149150USB DRIVE    1200003
3761005TAPE         5000004
2791010BOLTS        0000751
3000100STAPLER      0002007
3001101OVERHEAD PROJ0099997
3002099PENCILS      0000097
4001184CANADIAN RUGS0150294
4003050CARPET       0040000
4005001WASTE BASKETS0003793
5001010HINGES       0010001
5003010PENS (GOLD)  0049992
5004400PENS (BLACK) 0002004
8888999HIGH CHAIR   9999991
8889412PLAY PEN     0074992
0001001LOW TEST     0000019
9999999LAST RECORD  0000011

Answer 1

你的问题是：

01 WS-PERCENT-WITH-DISCOUNT PIC 99V9.

当你做除法时，你把结果存储在那个字段中。如果您期望它是0.556，您要存储的是0.5，因为您只定义了一个小数位，所以这两个低阶小数位只是被截断。

当你乘以100，你就可以得到50.0。

如果您用小数点三位来定义该字段，那么您的预期答案就会出现(我还没有检查您的数据)。

但是，更好的方法是定义更多的整数位数，这样字段就足够大，足以容纳中间结果，并首先乘以100。然后，您可以进行除法(您可能想考虑对其进行舍入，但这取决于程序的规范)。

这里有几个关于COMPUTE问题的问题。阅读这些问题并理解答案将有助于你很好地理解这些问题。在COBOL中，定义所需的准确性，并通过提供正确的整数和十进制数字来实现。

您还可以查看其他一些COBOL问题，在这些问题中，您将发现许多关于在文件中使用文件状态和检查每个IO的结果的建议。您还可以使用您定义的文件状态字段来检查文件的结束，而不是使用AT END/NOT AT END：您应该发现它需要更少的代码，并且更容易理解。

尽可能多地断掉句号/句号。您需要一个在PROCEDURE DIVISION头的末尾，一个在一个过程名的末尾，一个在一个过程的末尾，一个在程序的末尾(如果你没有过程名称)。其他的都是多余的。代码中的逗号容易分散注意力，您可能会发现使用缩进和语句格式会更清楚。

虽然它的构造很好，但是嵌套的-IF作为一个EVALUATE会更好。

程序中有许多常量。最好将其定义为数据项，并使用精心选择的名称，这样代码就可以“读取”，而且没有人会怀疑0.27的重要性。还有一些例子，其中有两个明显相关的常量，比如27.0和0.27，只要做一件事就更好了。如果某个人“维护”程序，他们只能更改其中一个值而不更改另一个值(而不是预期会有另一个值)。

还请看88级条件名称的使用情况。例如，“开关= y”可以变成“发票结束-文件”，而88可以处于该文件的文件状态，值为"10“。

你应该用一个空的输入文件来测试你的程序，看看你是否喜欢这个结果。

作为一个使用COBOL的初学者，它一点也不差。