Chapter 3
3-1
To familiarize you with
 Ways in which data is organized in COBOL
 Rules for forming data-names
 Defining input and output files in DATA
DIVISION
 Defining storage for work fields and
constants
 Forming Data-Names
 The FILE SECTION of the DATA DIVISION
 Types of Data
 WORKING-STORAGE SECTION of the DATA
DIVISION
3-2

Fully Interactive Programs
◦ Use ACCEPT to get input from keyboard
◦ Use DISPLAY to display output on screen

Full Batch Programs
◦ Get input from files on disk
◦ Direct output to files on disk

Hybrid Programs
◦ Use combination of interactive and batch input and
output methods
3-3

Field - group of characters forming a
meaningful unit or basic fact
◦ Characters in a name or digits in an amount

Records - group of related fields
◦ All fields related to customer

File - group of related records
◦ Customer file made up of customer records
3-4
1.
2.
3.
4.
5.
6.
Date-Of-Birth
Amount$Out
Section
-First-Name
98-6
Time out
3-6
1. Use
meaningful data-names that describe
contents of field
• Amount-Due-In instead of A1
2. Use
prefixes or suffixes in data-names when
appropriate
• -IN and -OUT for fields (Emp-Salary-IN and EmpSalary-OUT)
• -FILE and -RECORD for file and record names
(Emp-File and Emp-Record)
3-7


Defines, describes storage for all data
Two main sections
◦ FILE SECTION
 Defines all input and output files, records, fields
• Required for any program that uses files, typically
batch programs
◦ WORKING-STORAGE SECTION
 Defines constants, end-of-file indicators and work
areas
 Defines fields not part of input or output files
3-8
•
Input files
• Master files
• Transaction files -> updates
•
Output files
• New Master files -> mix the two to get
• Report files
3-9
•
•
•
Each file described with an FD (File
Descriptor) sentence
One FD for each SELECT statement in
ENVIRONMENT DIVISION
FD followed by
• File-name
• Optional clauses to describe file and format of its
records
310
FD
file-name
RECORD IS
OMITTED
LABEL
RECORDS ARE
STANDARD
RECORD CONTAINS integer-1 CHARACTERS
BLOCK CONTAINS integer-2 RECORDS .
311

LABEL RECORDS clause
◦ Used if labels stored in file (OS will handle this for
us, so we won’t use this clause)

BLOCKS CONTAINS clause
◦ Indicates blocking factor for disk files (We won’t be
using this clause) Has to do with disks that store
data relative to blocks.

Just in case you see it later.
312




Indicates size of each record
Optional but recommended since it provides
check on record size
Given this FD
FD Sales-File
Record Contains 75 Characters.
If PICTURE clauses mistakenly add up to 76,
compiler will report a syntax error
313
•
•
•
•
Each FD (File Descriptor) followed by record
description entries for the file
Data grouped in COBOL by levels
Record-name defined at the 01 level
• Considered highest level of data
Fields within a record defined at subordinate
level with level numbers from 02 to 49
314
01 Employee-Rec-In.
05 Name-In …
05 Annual-Salary-In …
05 Job-Description-In …
•
•
•
Fields at 05 level subordinate to 01 level
entry
All fields at same level (05), independent or
not subordinate to each other
Leave room in numbering in case you need
to add in between.
315
•
REVIEW:
•
•
•
•
SELECT names file, assigns it to hardware device
FD describes file
01 names record
02-49 describes fields within record
316

Items defined with a level number are one of
two types
◦ Elementary item - field that is not further
subdivided
 Must include a PICTURE clause
◦ Group item - field that is further subdivided
 Has no PICTURE clause
317
01 Employee-Rec-In.
05 Name-In …
10 First-Name-In (Picture clause)
10 Last-Name-In (Picture clause)
05 Annual-Salary-In (Picture clause)
•
•
•
Name-In is group item since it is
subdivided into first and last name
Employee-Rec-In also group item
First-Name-In is elementary item since it is
not further subdivided
318
01 Employee-Rec-In.
05 Name-In …
10 First-Name-In (Picture clause)
12 Last-Name-In (Picture clause)
05 Annual-Salary-In (Picture clause)
•
Last-Name-In level number is invalid since
it is not subordinate to First-Name-In
• Makes no sense because First-Name-In
wouldn’t have a PIC clause and same
indentation
•
Both first and last name are at same level
and should have same level number
319
•
•
Specify type of data stored in field
Indicate size of field
320
•
Alphabetic
•
Alphanumeric
•
Numeric
• Only letters or blanks
• For name, item description, etc.
• Any character - letters, digits, special characters
• For an address like 123 N. Main St.
• Only digits
• For fields used in arithmetic operations
321
•
•
•
A for alphabetic
X for alphanumeric
9 for numeric
322
Denote size of field by:
 Number of A’s, X’s or 9’s used in PICTURE
01 Cust-Rec-In.
05
05
Cust-ID-In Picture XXXX.
Amt-In
Picture 99999.
323
My also denote size of field by:
 A, X or 9 followed by number in parentheses
01 Cust-Rec-In.
05
05
Cust-ID-In Picture X(4).
Amt-In
Picture 9(5).
324




Must account for all positions defined in
record layout
Must describe fields in order they appear in
record
Field names should be unique
For fields not used by program
◦
◦
◦
◦
Data-name may be left blank (preferable)
May use reserved word FILLER as data-name
Positions must still be defined using PIC clause
Common for printing/display
325




For fields used in arithmetic operations
Symbol V used in PIC clause to denote
location of implied decimal point
Decimal point itself not stored as part of
number
To store value 26.79 in field AMT-IN, code
entry as
05 Amt-In Pic 99V99.
326
•
•
•
Entries in DATA DIVISION reserve storage for
data
Entries in FILE SECTION reserve storage for
data from records in input/output files
WORKING-STORAGE SECTION reserves
storage for keyed input/output
327
•
•
•
Data with a fixed value
Value that does not depend on input
Examples:
• Fixed tax rate of .05
• Message “INVALID” displayed when a value is in
error
•
.05 and “INVALID” are constant values
328
•
Numeric literal
• Examples: .05
5280
199.99
• Constant used for arithmetic operations
•
Nonnumeric (alphanumeric) literal
• Examples:
•
“INVALID”
“Enter your name”
Figurative constant
• SPACES
ZEROS
• Reserved word for commonly used values
329
•
•
•
Must be enclosed in quotation marks
From 1 to 160 characters, including space
Any character in COBOL character set
except quotation mark
Valid Nonnumeric Literals
'123 Main St.'
'12,342'
'$14.99'
'Enter a value from 1 to 10'
330


Only characters within quotes are moved or
displayed
May contain all numbers ('125') but not same
as numeric literal (125)
◦ Cannot be used in arithmetic operations
◦ Cannot be moved to field with PIC of 9’s

Are not data-names
◦ 'Amount-In' not same as field defined in DATA
DIVISION called Amount-In
331



ZERO, ZEROS or ZEROES means all zeros
Example
Move Zeros To Total-Out
Fills each position in Total-Out with a zero
May be used with both numeric and
alphanumeric fields
332
SPACE or SPACES means all spaces or blanks
Example
Move Spaces To Code-Out



Fills each position in Code-Out with a space
or blank
Use only with alphanumeric fields since blank
is invalid numeric character
333




Follows FILE SECTION
Begins with heading on line by itself
Starts in Area A, ends with period
All items must be defined at 01 level or in
entries subordinate to 01 level entry
334


Rules for user-defined data-names apply
Elementary items:
◦ Must include PICTURE clause
◦ May be assigned initial value with VALUE clause
335
To define fields used for
 Keyed input and displayed output
 Intermediate arithmetic results
 Counters and totals
 End-Of-File Indicators
336



To define initial value for field
If omitted, field’s value undefined when
program begins execution
May be used only in WORKING-STORAGE
SECTION
337

VALUE clause used in DATA DIVISION
◦ Gives initial value before execution begins

MOVE used in PROCEDURE DIVISION
◦ Assigns value to field after program begins

MOVE may change initial value of field
338



Contains literal or figurative constant
Data type must match PICTURE
Numeric literals or ZEROS used with PIC 9
fields
01 WS-Tax-Rate Pic V99 Value .06.
01 WS-Total
Pic 999 Value Zeros.

Nonnumeric literals, ZEROS or SPACES used
with PIC X fields
01 WS-EOF
Pic X(3) Value ‘YES’.
01 WS-Descrip Pic X(8) Value Spaces.
339
Define a literal of .28 (28%) for a tax rate

Method 1 - code as literal in PROCEDURE
DIVISION
Multiply .28 by WS-Salary Giving WS-Tax

Method 2 - store in data item in WORKINGSTORAGE SECTION
01 WS-Rate Pic V99 Value .28.
340

Method 2 - use data-name in place of literal
in PROCEDURE DIVISION
Multiply WS-Rate by WS-Salary Giving
WS-Tax
◦ Preferable for literals used more than once
◦ Reduces likelihood of error since literal value
entered one time
◦ Allows meaningful name to be associated with
number
341




Nonnumeric literals may be up to 160
characters
Long literals may not fit on one typed line
Subdividing long literals into separate fields
is recommended
You may need this when making a long
sentence.
342
Example
Separate this report title into two fields
"Transaction Report for XYZ Corporation"
01 Report-Title.
05
Pic X(18) Value 'Transaction Report'.
05
Pic X(20) Value ' for XYZ Corporation'.
343


Long literals may be continued from one
line to next, although this is not
recommended
Rules for continuation of literals from one
line to next
◦ Begin literal with quotation mark.
◦ Continue literal to position 72. Do not end with
quotation mark.
◦ Place hyphen on next line in position 7.
◦ Continue literal with quotation mark starting
anywhere in Area B.
◦ End literal with quotation mark.
◦ Example p. 92
344
1.
2.
3.
4.
5.
LABEL RECORDS clause will be phased out
entirely
VALUE clause will be allowed in FILE
SECTION
Way to continue nonnumeric literals will
change
Margins A and B rules will be guidelines
rather than requirements
Commas and dollar signs will be
permissible in numeric literals
345



Data organized into files, records and fields
Variable data changes with each run
depending on input values
Constant or literal data defined within
program, not entered as input
346




FILE SECTION includes FD entry for each file
used by program
Record names coded at 01 level
Field names coded at 02-49 level
Fields must be defined in order they appear
in record
347




Group items are further subdivided
Elementary items are not subdivided
Elementary items have PICTURE clause
Codes X, A, 9, V used to describe data
348

WORKING-STORAGE SECTION used for storing
◦ Intermediate results, counters
◦ End-of-file indicators
◦ Interactive data accepted as input or displayed

VALUE clauses may be used in this section to
initialize fields
349