【发布时间】：2020-10-14 20:07:24
【问题描述】：
Cobol 批处理程序存在问题，它仅从输入文件中读取一行，并且正在读取的行也不是第一行。输入文件的记录是固定长度的。 代码是：
IDENTIFICATION DIVISION.
PROGRAM-ID. AverageGPA.
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT STUDENT-DATA
ASSIGN TO "C:\COBOL\CH0708.DAT"
ORGANIZATION IS LINE SEQUENTIAL.
SELECT OUTPUT-FILE
ASSIGN TO "C:\COBOL\STUDENT_GPA.DAT"
ORGANIZATION IS LINE SEQUENTIAL.
DATA DIVISION.
FILE SECTION.
FD STUDENT-DATA.
01 EMPLOYEE-RECORD.
05 SSN-IN PICTURE X(9).
05 NAME-IN PICTURE X(21).
05 CLASS-IN PICTURE 9.
05 SCHOOL-IN PICTURE 9.
05 GPA-IN PICTURE 9V99.
05 CREDITS-IN PICTURE 999.
FD OUTPUT-FILE.
01 OUTPUT-DATA.
05 SSN-OUT PICTURE X(9).
05 PICTURE X(5).
05 NAME-OUT PICTURE X(21).
05 CLASS-OUT PICTURE X(9).
05 PICTURE X(5).
05 SCHOOL-OUT PICTURE X(15).
05 PICTURE X(5).
05 GPA-OUT PICTURE 9.99.
05 PICTURE X(5).
05 CREDITS-OUT PICTURE Z99.
WORKING-STORAGE SECTION.
01 OUTPUT-HEADING.
05 SSN-HEADING PICTURE X(9)
VALUE 'SSN'.
05 PICTURE X(5).
05 NAME-HEADING PICTURE X(21)
VALUE 'STUDENT NAME'.
05 CLASS-HEADING PICTURE X(9) VALUE 'CLASS'.
05 PICTURE X(5).
05 SCHOOL-HEADING PICTURE X(15) VALUE 'SCHOOL'.
05 PICTURE X(5).
05 GPA-HEADING PICTURE X(3) VALUE 'GPA'.
05 PICTURE X(5).
05 CREDITS-HEADING PICTURE X(7) VALUE 'CREDITS'.
01 GPA-COUNT PICTURE 9 VALUE 0.
01 GPA-SUM PICTURE 9V99 VALUE 0.
01 AVERAGE-GPA PICTURE 9.99.
01 AVERAGE-GPA-LINE PICTURE X(16)
VALUE 'AVERAGE GPA IS '.
01 ARE-THERE-MORE-RECORDS PICTURE XXX VALUE 'YES'.
PROCEDURE DIVISION.
100-MAIN-MODULE.
OPEN INPUT STUDENT-DATA
OUTPUT OUTPUT-FILE
WRITE OUTPUT-DATA FROM OUTPUT-HEADING
PERFORM UNTIL ARE-THERE-MORE-RECORDS = 'NO '
READ STUDENT-DATA
AT END
MOVE 'NO' TO ARE-THERE-MORE-RECORDS
NOT AT END
PERFORM 200-WRITE-GPA
END-READ
END-PERFORM
DIVIDE GPA-SUM BY GPA-COUNT GIVING AVERAGE-GPA
WRITE OUTPUT-DATA FROM AVERAGE-GPA-LINE
WRITE OUTPUT-DATA FROM AVERAGE-GPA
CLOSE STUDENT-DATA
OUTPUT-FILE
STOP RUN.
200-WRITE-GPA.
MOVE SPACES TO OUTPUT-DATA.
MOVE SSN-IN TO SSN-OUT
MOVE NAME-IN TO NAME-OUT
IF CLASS-IN = 1
MOVE 'FRESHMAN' TO CLASS-OUT
ELSE IF CLASS-IN = 2
MOVE 'SOPHOMORE' TO CLASS-OUT
ELSE IF CLASS-IN = 3
MOVE 'JUNIOR' TO CLASS-OUT
ELSE IF CLASS-IN = 4
MOVE 'SENIOR' TO CLASS-OUT
ELSE
MOVE CLASS-IN TO CLASS-OUT
END-IF
IF SCHOOL-IN = 1
MOVE 'BUSINESS' TO SCHOOL-OUT
ELSE IF SCHOOL-IN = 2
MOVE 'LIBERAL ARTS' TO SCHOOL-OUT
ELSE IF SCHOOL-IN = 3
MOVE 'ENGINEERING' TO SCHOOL-OUT
ELSE
MOVE 'INVALID' TO SCHOOL-OUT
END-IF
MOVE GPA-IN TO GPA-OUT
ADD GPA-IN TO GPA-SUM
MOVE CREDITS-IN TO CREDITS-OUT
ADD 1 TO GPA-COUNT
WRITE OUTPUT-DATA.
STOP RUN.
输入文件是：
125997600R. HENDERSON 11379011
234789543P. MARTINSON 11250011
276888003M. JACKSON 22394020
332557267B. BRUHANSKY 21314020
235654654K. THOMPSON 23279021
336221180F. SMITH 21304019
332557845D. MIKA 33217024
377000854A. ABRAMS 31379027
399000002L. NAIRN 33375029
211311411P. BUTTRAM 41397035
122886567F. DARK 41297034
224257889S. SMITH 41397038
125654334C. HAYES 41400040
345345669J. FISHER 42200036
432234543S. JONES 43291033
488345612M. PILLION 41255034
给出的输出是
SSN STUDENT NAME CLASS SCHOOL GPA CRED
432234543 S. JONES SENIOR ENGINEERING 2.91 33
AVERAGE GPA IS
2.91
另外，还有两个问题。 为什么学分标题没有显示所有字母？我将如何为平均 GPA 做好准备？现在它在两条线上，但我希望它在一条线上。
【问题讨论】：
-
您在 200-WRITE-GPA 中有一个 STOP RUN，因此它将在第一次执行该段落时停止执行。此外，您的输出中的名称 (S> JONES) 不会出现在您列出的输入中。您确定向我们展示了正确的文件吗？
-
这是正确的文件，它是倒数第二行。至于 STOP RUN，如果最后一行不存在，我会收到一条错误消息，提示文件意外结束。
-
刚刚在 WRITE OUTPUT-DATA 之后添加了另一行，现在它可以工作了。
-
而且仍然以某种方式只显示 S. Jones 线。
-
在最后一行出错并不是在第一行执行 STOP RUN 的理由。
标签： cobol