我正在为我的课程完成一项作业，而我在获取百分比以显示COBOL实验室的正确价值方面存在问题。
我的问题是PERCENT-DISCOUNT / WS-PERCENT-WITH-DISCOUNT（至少，我相信它是）。
当程序运行时，我得到结果50.0。我应该得到的结果（假设我手动正确地进行了数学运算）是55.6。我不太确定我哪里出错了。
以下是我目前为该计划编写的代码。
*
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
答案 0 :(得分：6)
你的问题在这里：
01 WS-PERCENT-WITH-DISCOUNT PIC 99V9.
当您进行除法时，将结果存储在该字段中。如果你期望它是0.556，你存储的是0.5，因为你只定义了一个小数位，所以两个低位小数位被简单地截断。
当你乘以100时，你得到50.0。
如果您定义具有三个小数位的字段，则应显示您的预期答案（我没有检查您的数据）。
然而，更好的方法是定义更多整数位，以便该字段足够大以容纳中间结果并先乘以100 。然后你可以划分（你可能想考虑ROUNDED，但这取决于程序的规范）。
此处有一些关于COMPUTE问题的问题。阅读这些问题并理解答案将有助于您掌握这些问题。在COBOL中，你定义所需的准确度，并通过提供正确数量的整数和小数位来实现。
您还可以查看其他一些COBOL问题，在这些问题中，您可以找到有关在文件上使用FILE STATUS以及检查每个IO的结果的大量建议。您还可以使用您定义的文件状态字段来检查文件结尾，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。
尽可能多地完全停止/停止。在PROCEDURE DIVISION标题的末尾需要一个，一个在过程名称的末尾，一个在过程的末尾，一个在程序的末尾（如果没有过程名称） 。所有其他都是多余的。代码中的逗号往往会分散注意力，您可能会发现使用缩进和语句格式更清晰。
虽然构造良好，但您的嵌套 - IF会更好EVALUATE。
你的程序中有很多常量。最好将它们定义为具有良好选择名称的数据项，以便代码“读取”，并且没有人不得不怀疑0.27的重要性。你也有一些例子，你有两个明显相关的常数，例如27.0和0.27，只需要做一件事就可以得到更好的服务。如果某人“维护”了该程序，他们可能只会更改其中一个值而不会更改另一个值（不要期望有另一个值）。
另请参阅使用88级条件名称。例如，“switch = y”可以成为“发票结束文件”，而88可以是该文件的文件状态，值为“10”。
您应该使用空输入文件测试您的程序，看看您是否喜欢这些结果。
作为COBOL的初学者，它根本不是一个糟糕的镜头。