Transcript Programming in COBOL

Programming in
COBOL-85
For IBM Mainframe
System 390
Jyothi Sridhar Kini
E&R, Infosys
Mail-id: [email protected]
Phone: 52179
Course Plan

Day 1: Introduction to COBOL

Day 2: Cobol Language constructs

Day 3: Sequential File Handling

Day 4: Index sequential file handling,
COPY, CALL

Day 5,6,7:
Working on project
Pre-requisites
 Programming Fundamentals.
 MVS Operating system and its subsystem TSO.
 Job Control Language to submit jobs to MVS.
 Navigating through ISPF.
Topics beyond the scope

Report writer feature of COBOL
References
TITLE
AUTHOR
PUBLISHER
COBOL
Programming
M.K.Roy and
D. Ghosh
Dastidar
Tata McGraw Hill
COBOL
Programming
Nancy Stern and
Robert Stern
John Wiley & Sons Inc
Programming
with
Structured
COBOL
Newcomer and
Lawrence
McGraw Hill Books
(Schaum Series)
Any Time reference IBM manuals
Agenda for Day 1
 Evolution and Features of COBOL.
 General Coding and Format rules.
 Language Fundamentals.
 Input and Output verbs.
 Arithmetic verbs.
 Design and development of simple COBOL programs
History of COBOL
 Early years.
 ANS Versions of COBOL.
 Future of COBOL.
http://www.home.swbell.net/mck9/cobol/cobol.html
http://www.infogoal.com/cbd/cbdhome.html
History of COBOL
 1960 – COBOL (Common Business Oriented Language)
initial specifications presented by CODASYL (Conference
on Data System Languages)
 1964 – revised to make COBOL more flexible
 1968 – ANSI (American National Standards Institute)
developed American National Standard (ANS) COBOL
– Standardized form
– Attempted to overcome incompatibilities of different
versions of COBOL
 1974 – ANSI published revised version of (ANS) COBOL
– Business applications needed to manipulate character as
well as numeric data
– String operations added
History of COBOL
 1985 – ANSI published another revised
version of COBOL
– Designed to take advantage of structured
programming techniques
– Logic errors reduced with END statements
– Case statement reduced nested IFs
– Less English-like
– Maintained readability and business orientation
– Compatible with previous versions
COBOL
 COBOL is an acronym which stands for
COmmon Business Oriented Language.
 The name indicates the target area of COBOL
applications.
 COBOL is used for developing business,
typically file-oriented, applications.
 It is not designed for writing systems programs.
You would not develop an operating system or a
compiler using COBOL.
 COBOL is one of the oldest computer languages
in use (it was developed in late 1950s).
CODSYL
Nature of COBOL
 Business Oriented Language.
 Standard Language.
 Robust Language.
 Structured Programming Language.
 English-like Language.
Structure of a COBOL program
PROGRAM
SENTENCES
DIVISIONS
STATEMENTS
SECTIONS
PARAGRAPHS
RESERVED
WORDS
USER DEFINED
WORDS
CHARACTERS
COBOL Character set

Alphabets (Both upper and lower case)

Digits (0 to 9)

Special characters
b
-
+
*
/
=
$
,
;
.
“
‘
<
>
(
)
The COBOL DIVISIONs
DIVISIONS are used to identify the principal
components of the program text. There are four
DIVISIONS in all.
 IDENTIFICATION DIVISION.
 ENVIRONMENT DIVISION.
// Optional
 DATA DIVISION.
// Optional
 PROCEDURE DIVISION.
IDENTIFICATION DIVISION
 The purpose of the IDENTIFICATION
DIVISION is to provide information
about the program to the programmer
and to the compiler.
 Most of the entries in the
IDENTIFICATION DIVISION are
directed at the programmer and are
treated by the compiler as comments.
IDENTIFICATION DIVISION...
 An exception to this is the PROGRAMID clause. Every COBOL program must
have a PROGRAM-ID. It is used to
enable the compiler to identify the
program.
 There are several other informational
paragraphs in the IDENTIFICATION
DIVISION but we will ignore them for
the moment.
IDENTIFICATION DIVISION...
 The IDENTIFICATION DIVISION has
the following structure
IDENTIFICATION DIVISION.
PROGRAM-ID. PGM-NAME.
[AUTHOR. YourName.]
IDENTIFICATION DIVISION.
PROGRAM-ID. FIRSTPGM.
AUTHOR. Michael Coughlan.
IDENTIFICATION DIVISION...
The keywords IDENTIFICATION DIVISION
represent the division header and signal the
commencement of the program text.
The paragraph name PROGRAM-ID is a
keyword. It must be specified immediately after the
division header.
The program name can be up to 8 characters long
on MF(30 in case of windows).
IDENTIFICATION DIVISION...
Is used to identify the program to the computer.
Is the least significant DIVISION of a COBOL
program.
IDENTIFICATION DIVISION.
PROGRAM-ID. Member-name. ( Max 8 chars, letters & digits only )
AUTHOR.
/ Optional entry
INSTALLATION.
/ Optional entry
DATE-WRITTEN.
/ Optional entry
DATE-COMPILED.
/ Optional entry
ENVIRONMENT DIVISION
 The ENVIRONMENT DIVISION is totally
optional unless you want to use files /
specify special devices to the compiler in
ENVIRONMENT DIVISION.
your program.
CONFIGURATION SECTION.
 IsSOURCE-COMPUTER.
used to indicate the Specific
Computers
VAX-6410.
OBJECT-COMPUTER.
IBM-ES9000.
used
to develop and execute
the program.
INPUT-OUTPUT
SECTION.
The
general format
of ED is
FILE-CONTROL.
SELECT EMPL-FILE ASSIGN TO
DISC.
...
The DATA DIVISION
 The DATA DIVISION is used to describe most
of the data that a program processes.
 The DATA DIVISION has two main sections– FILE SECTION.
– WORKING-STORAGE SECTION.
 The FILE SECTION is used to describe most of
the data that is sent to, or comes from, the
computer’s peripherals.
 The WORKING-STORAGE SECTION is used
to describe the general variables used in the
program.
DATA DIVISION
Is used to describe the structure of the fields,
records, files and temporary variables used for
calculations.
DATA DIVISION.
/ Optional entry
FILE SECTION.
FD filename
. . . . . . .
SD sortfile
. . . . . . .
WORKING-STORAGE SECTION.
. . . . . . .
PROCEDURE DIVISION
 Is the most significant DIVISION of a
COBOL program.
 Includes statements and sentences
necessary for reading input, processing it
and writing the output. These are the
instructions that are executed by the
computer at the RUN TIME.
PROCEDURE DIVISION…
 The PROCEDURE DIVISION is where
all the data described in the DATA
DIVISION is processed and produced
desired results. It is here that the
programmer describes his algorithm.
 The PROCEDURE DIVISION is
hierarchical in structure and consists of
Sections, Paragraphs, Sentences and
Statements.
PROCEDURE DIVISION...
 Only the Section is optional. There must
be at least one paragraph, sentence and
statement in the PROCEDURE
DIVISION .
 In the PROCEDURE DIVISION,
paragraph and section names are chosen
by the programmer.
 The names used should reflect the
processing being done in the paragraph or
section.
Sections
 A SECTION is a block of code made up of one
or more paragraphs.
 A SECTION begins with the section-name and
ends where next section name is encountered or
where the program text ends.
 A SECTION name consists of a name devised
by the programmer or defined by the language
followed by the word SECTION followed by a
full stop.
– U0000-SELECT-USER-RECORDS SECTION.
– FILE SECTION.
Paragraphs
 Each section consists of one or more paragraphs.
 A PARAGRAPH is a block of code made up of
one or more sentences.
 A PARAGRAPH begins with the paragraphname and ends with the next paragraph or section
name or the end of the program text.
 The paragraph-name consists of a name devised
by the programmer or defined by the language
followed by a full stop.
– P0000-PRINT-FINAL-TOTALS.
– PROGRAM-ID.
Sentences and Statements
 A PARAGRAPH consists of one or more sentences.
 A SENTENCE consists of one or more statements and is terminated by
a full stop.
– MOVE .21 TO VAT-RATE
COMPUTE VAT-AMOUNT = PRODUCT-COST * VAT-RATE.
– DISPLAY "Enter Name " WITH NO ADVANCING
ACCEPT STUDENT-NAME
DISPLAY "Name Entered was " STUDENT-NAME.
 A STATEMENT consists of a COBOL verb and an operand or
operands.
– SUBTRACT T-TAX FROM GROSS-PAY GIVING NET-PAY
– READ STUDENT-FILE
AT END SET END-OF-FILE TO TRUE
END-READ
First COBOL program
IDENTIFICATION DIVISION.
PROGRAM-ID.FIRSTPGM.
AUTHOR. Michael Coughlan.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 WS-NUM-1
PIC 9(001) VALUE ZEROS.
01 WS-NUM-2
PIC 9(001) VALUE ZEROS.
01 WS-RESULT-1 PIC 9(002) VALUE ZEROS.
PROCEDURE DIVISION.
A0000-MAIN-PARA.
ACCEPT WS-NUM-1
ACCEPT WS-NUM-2
MULTIPLY WS-NUM-1 BY WS-NUM-2 GIVING
WS-RESULT-1
DISPLAY "Result is = ", WS-RESULT-1
STOP RUN
.
The minimum COBOL program
IDENTIFICATION DIVISION.
PROGRAM-ID. SMALLPGM.
PROCEDURE DIVISION.
A0000-DISPLAY-PARA.
DISPLAY "I did it."
STOP RUN
.
What is the model we have used to
describe the
TOP-DOWN
COBOL program structure?
COBOL coding rules
 Almost all COBOL compilers treat a line of
COBOL code as if it contained two distinct areas.
These are known as; Area A and Area B
 When a COBOL compiler recognizes these two
areas, all division, section, paragraph names, FD
entries and 01 level entries must start in Area A.
All other sentences/statements must start in Area B.
 Area A is four characters wide and is followed by
Area B.
COBOL coding rules...
 In some COBOL compilers these coding
restrictions are removed.
– For example In Microfocus COBOL compiler
directive
$ SET SOURCEFORMAT"FREE" frees us
from
all formatting restrictions.
$ SET SOURCEFORMAT"FREE"
IDENTIFICATION DIVISION.
PROGRAM-ID. ProgramFragment.
* This is a comment. It starts
* with an asterisk in column 1
COBOL coding sheet
Column numbers
1 2 3 4 5 6 7 8 9 10 11 12
Column
numbers
* Area A
/
Area B
72
80
I
D
E
N
T
I
F
I
C
A
T
I
O
N
A
R
E
A
COBOL coding rules
 Each line is considered to be made up of 80
columns.
 Columns 1 to 6 are reserved for line numbers.
 Column 7 is an indicator column and has special
meaning to the compiler.
Asterisk ( * ) indicates comments
Hyphen ( - ) indicates continuation
Slash ( / ) indicates form feed
COBOL coding rules
 Columns 8 to 11 are called Area A. All
COBOL DIVISIONs, SECTIONs,
paragraphs and some special entries must
begin in Area A.
 Columns 12 to 72 are called Area B. All
COBOL statements must begin in Area B.
 Columns 73 to 80 are identification area.
COBOL data description
 COBOL uses what could be described as a
“declaration by example” strategy.
 In effect, the programmer provides the
system with an example, or template, or
PICTURE of what the data item looks like.
 From the “picture” the system derives the
information necessary to allocate it.
Basic data types
 Alphabetic
 Numeric
 Alphanumeric
 Edited numeric
 Edited alphanumeric
Literals
 Literals are symbols whose value does not
change
in a program.
 There are 3 types of literals namely
(1) Numeric literals.
(2) Non-numeric literals.
(3) Figurative constants.
Literals
Numeric literals
 Are formed using digits only.
 May include a sign which must be the extreme
left character.
 There must not be any blank between the sign
and
the first digit.
 May include a decimal point which can not be
the
right most character.
 Can have at most 18 digits.
Literals
Non-numeric literals
 Are used display headings or messages.
 Are a sequence of characters (except quotes)
from
the COBOL character set enclosed within
quotes.
 May contain up to 160 characters including
spaces.
Literals
Figurative constants
Figurative constants
Meaning
ZERO(S) or ZEROES
Represents the value 0, one or
more depending on the context
SPACE(S)
Represents one or more spaces
HIGH-VALUE(S)
Represents the highest value
LOW-VALUE(S)
Represents the lowest value
QUOTE(S)
Represents single or double
quotes
Data names
 Are named memory locations.
 Must be described in the DATA
DIVISION before they can be used in the
PROCEDURE DIVISION.
 Can be of elementary or group type.
 Can be subscripted.
 Are user defined words.
Rules for forming User-defined
words
 Are used to form section, paragraph and data
names.
 Can be at most 30 characters in length.
 Only alphabets, digits and hyphen are allowed.
 Blanks are not allowed.
 May not begin or end with a hyphen.
 Should not be a COBOL reserved word.
Description of data names
 All the data names used in the PROCEDURE
DIVISION must be described in the DATA
DIVISION.
 The description of a data name is done with the
aid of
(1) Level number
(2) PICTURE clause
(3) VALUE clause
Description of data names
Level number
 Is used to specify the the data hierarchy.
Level Number
01
02 to 49
Purpose
Record description and independent items
Fields within records and sub items
66
RENAMES clause
77
Independent items
88
Condition names
Description of data names
PICTURE clause
 Is used to specify the following
(1) The data type
(2) The storage requirement.
 Can be abbreviated as PIC.
 Can be abbreviated in case of recurring
symbols.
 Is used only elementary items.
Description of data names
PICTURE clause
Code
Meaning
9
Numeric
A
Alphabetic
X
Alphanumeric
V
Decimal Point
S
Sign bit
Description of data names
VALUE clause
 Is used to assign an initial value to a
elementary data item.
 The initial value can be numeric literal,
non- numeric literal or figurative constant.
 Is an optional clause.
Group and elementary items
 In COBOL the term “group item” is used to
describe a data item which has been further
subdivided.
– A Group item is declared using a level
number and a data name. It cannot have
a picture clause.
– Where a group item is the highest item in
a data hierarchy it is referred to as a
record and uses the level number 01.
Group and elementary items..
 The term “elementary item” is used to describe
data items which are atomic, that is, not further
subdivided.
 An elementary item declaration consists of;
• a level number,
• a data name
• picture clause.
An elementary item must have a picture clause.
 Every group or elementary item declaration must
be followed by a full stop.
PICTURE Clauses for Group Items
 Picture clauses are NOT specified for ‘group’
data items because the size of a group item is
the sum of the sizes of its subordinate,
elementary items and its type is always
assumed to be PIC X.
 The type of a group items is always assumed to
be PIC X, because group items may have
several different data items and types
subordinate to them.
 An X picture is the only one which could
support such collections.
Group Items/Records - Example
WORKING-STORAGE SECTION.
01 STUDENT-DETAILS
PIC X(026).
STUDENT-DETAILS
H E N N E S S Y R M 9 2 3 0 1 6 5 L M 5 1 0 5 5 0 F
Group Items/Records - Example
WORKING-STORAGE SECTION.
01 STUDENT-DETAILS.
02 STUDENT-NAME
02 STUDENT-ID
02 COURSE-CODE
02 GRANT
02 GENDER
PIC
PIC
PIC
PIC
PIC
X(010).
9(007).
X(004).
9(004).
X(001).
STUDENT-DETAILS
H EN N E S S Y RM 9 2 3 0 1 6 5 L M 5 1 0 5 5 0 F
STUDENT-NAME
STUDENT-ID
COURSE-CODE GRANT GENDER
Group Items/Records
WORKING-STORAGE SECTION.
01 STUDENT-DETAILS.
02 STUDENT-NAME.
03 SURNAME
03 INITIALS
02 STUDENT-ID
02 COURSE-CODE
02 GRANT
02 GENDER
PIC
PIC
PIC
PIC
PIC
PIC
X(008).
X(002).
9(007).
X(004).
9(004).
X(001).
STUDENT-DETAILS
H EN N E S S Y RM 9 2 3 0 1 6 5 L M 5 1 0 5 5 0 F
STUDENT-NAME
SURNAME
STUDENT-ID
INITIALS
COURSE-CODE GRANT GENDER
LEVEL Numbers & DATA
hierarchy
01
 In COBOL, level numbers are used to decompose
a structure into it’s constituent parts.
 In this hierarchical structure the higher the level
number, the lower the item is in the hierarchy. At
the lowest level the data is completely atomic.
 The level numbers 01 through 49 are general level
numbers, but there are also special level numbers
such as 66, 77 and 88.
 In a hierarchical data description what is important
STUDENT-DETAILS.
01 STUDENT-DETAILS.
is
the
relationship
of
the
level
numbers to one
02 STUDENT-NAME.
05 STUDENT-NAME.
03 SURNAME
PIC X(008).
10 SURNAME
PIC X(008).
not
the
actual
level
numbers
used.
03another,
INITIALS
PIC
X(002).
10
INITIALS
PIC X(002).
02 STUDENT-ID
PIC 9(007).
05 STUDENT-ID
PIC 9(007).
02
02
02
COURSE-CODE
GRANT
GENDER
PIC X(004).
PIC 9(004).
PIC X(001).
05
05
05
COURSE-CODE
GRANT
GENDER
PIC X(004).
PIC 9(004).
PIC X(001).
Description of data names
Example
DATA DIVISION.
WORKING-STORAGE SECTION.
01 WS-REGNO
PIC X(5).
01 WS-NAME.
05 WS-FIRST-NAME PIC A(15).
05 WS-MID-NAME PIC A(15).
05 WS-LAST-NAME PIC A(10).
01 WS-AGE
PIC 99V99.
01 WS-SCHOLARSHIP
PIC 9(4)
VALUE 1000.
Break
Edited picture symbols
Edit symbol
Meaning
Z
Zero suppression
*
Check protection
,
Comma insertion
-
Minus sign insertion
+
Plus or minus sign insertion
Edited picture symbols
Edit symbol
$
Meaning
Dollar sign insertion
CR
Credit symbol
DB
Debit symbol
B
Blank insertion
/
Slash insertion
.
Decimal point insertion
BLANK WHEN ZERO
Blank insertion when
the value is zero.
PROCEDURE DIVISION Verbs
 Data movement verb.
 Arithmetic Verbs.
 Input / Output Verbs.
 Sequence control verbs.
 File handling verbs.
Input / Output Verbs
 ACCEPT Verb
Syntax
ACCEPT identifier [ FROM {
DATE, DAY, TIME, mnemonic-name }].
Examples
(1) ACCEPT NUMBER-1.
(2) ACCEPT TODAY-DATE FROM
DATE.
Input / Output Verbs
 DISPLAY Verb
Syntax
DISPLAY { identifier-1, literal-1 } , . . .
Examples
(1) DISPLAY “The sum is ” SUM.
Arithmetic Verbs
ADD
SUBTRACT
MULTIPLY
DIVIDE
COMPUTE
ADD Verb
Syntax-1
ADD { identifier-1, literal-1 } [ , identifier-2,
literal-2 ] . . . TO identifier-3 [ , identifier-4 ] . . .
Syntax-2
ADD { identifier-1, literal-1 } { identifier-2, literal-2
} [ identifier-3, literal-3 ] GIVING identifier-4 . . .
ADD Verb
Examples
(1) ADD NUM-1 TO NUM-2.
(2) ADD NUM-1, NUM-2 TO NUM-3.
(3) ADD 12, NUM-1, NUM-2 TO NUM-3, NUM-4.
(4) ADD NUM-1, NUM-2 GIVING NUM-3.
(5) ADD 12, NUM-1 GIVING NUM-2, NUM-3.
ADD Examples
Before
After
Before
After
Before
After
Before
After
ADD Cash TO Total.
3
1000
3
1003
ADD Cash, 20 TO Total, Wage.
3
1000
100
3
1023
123
ADD Cash, Total GIVING Result.
3
1000
0015
3
1000
1003
ADD Males TO Females GIVING TotalStudents.
1500
0625
1234
1500
0625
2125
SUBTRACT Verb
Syntax
SUBTRACT { identifier-1, literal-1 } [ identifier-2,
literal-2 ] . . . FROM identifier-3 [ , identifier-4 ]
[ , GIVING identifier-5 [ , identifier-6 ] . . . ]
SUBTRACT Verb
Examples
(1) SUBTRACT NUM-1 FROM NUM-2.
(2) SUBTRACT NUM-1, NUM-2 FROM NUM-3.
(3) SUBTRACT 5, NUM-1 FROM NUM-2, NUM-3.
(4) SUBTRACT 12 FROM NUM-1 GIVING NUM2.
(5) SUBTRACT NUM-1 FROM NUM-2 GIVING
NUM-3.
SUBTRACT Examples
Before
After
Before
After
Before
After
SUBTRACT Tax FROM GrossPay, Total.
120
4000
9120
120
3880 9000
SUBTRACT Tax, 80 FROM Total.
100
480
100
300
SUBTRACT Tax FROM GrossPay GIVING NetPay.
750
1000
0012
750
1000
0250
MULTIPLY Verb
Syntax
MULTIPLY { identifier-1, literal-1 } BY identifier-2
[ identifier-3 ] . . . [ , GIVING identifier-4
[ , identifier-5 ] . . . ]
MULTIPLY Verb
Examples
(1) MULTIPLY NUM-1 BY NUM-2.
(2) MULTIPLY NUM-1 BY NUM-2 GIVING
NUM-3.
(3) MULTIPLY 5 BY NUM-1 GIVING NUM-2.
(4) MULTIPLY NUM-1 BY NUM-2 GIVING
NUM-4, NUM-5.
DIVIDE Verb
Syntax-1
DIVIDE { identifier-1, literal-1 } INTO identifier-2
[ , identifier-2 ] . . . [ GIVING identifier-4
[ , identifier-5 ] . . . ] ..
Syntax-2
DIVIDE { identifier-1, literal-1 } BY { identifier-2,
literal-2 } GIVING identifier-3 [ , identifier-4 ].
DIVIDE Verb
Syntax-3
DIVIDE { identifier-1, literal-1 } { INTO , BY }
{ identifier-2, literal-2 } GIVING identifier-3
REMAINDER identifier-4 .
DIVIDE Verb
Examples
(1) DIVIDE 5 INTO NUM-1.
(2) DIVIDE 6 INTO NUM-1 GIVING NUM-2,
NUM-3.
(3) DIVIDE NUM-1 BY 3 GIVING NUM-2, NUM-3.
(4) DIVIDE NUM-1 BY NUM-2 GIVING NUM-3.
(5) DIVIDE NUM-1 BY NUM-2 GIVING NUM-3
REMAINDER NUM-4.
MULTIPLY and DIVIDE
MULTIPLY Subs BY Members GIVING TotalSubs
ON SIZE ERROR DISPLAY "TotalSubs too small"
END-MULTIPLY.
Before
After
Before
After
Before
After
Subs
Members
TotalSubs
15.50
100
0123.45
15.50
100
1550.00
MULTIPLY 10 BY Magnitude, Size.
355
125
3550
1250
DIVIDE Total BY Members GIVING Average ROUNDED.
9234.55
100
1234.56
9234.55
100
92.35
ROUNDED Option
Syntax
Arithmetic statement [ ROUNDED ].
Examples
(1) ADD NUM-1, NUM-2, NUM-3 GIVING NUM-4
ROUNDED.
(2) DIVIDE NUM-1 BY NUM-2 GIVING NUM-3
ROUNDED.
The ROUNDED
option
Receiving Field Actual Result Truncated Result Rounded Result
PIC 9(3)V9.
123.25
123.2
123.3
PIC 9(3).
123.25
123
123

The ROUNDED option takes effect when, after
decimal point alignment, the result calculated must
be truncated on the right hand side.

The option adds 1 to the receiving item when the
leftmost truncated digit has an absolute value of 5
or greater.
ON SIZE ERROR Option
Syntax
Arithmetic statement [ON SIZE ERROR imperative
statement . . .]
Examples
(1) ADD NUM-1, NUM-2, NUM-3 TO NUM-4 ON SIZE
ERROR PERFORM 900-EXIT-PARA.
(2). DIVIDE NUM-1 BY NUM-2 ON SIZE ERROR
PERFORM 800-ERROR-PARA.
On size error option
Receiving Field
PIC 9(3)V9.
PIC 9(3)V9.
Actual Result
245.96
1245.9
PIC 9(3).
124
PIC 9(3).
1246
PIC 9(3)V9 Not Rounded
124.45
PIC 9(3)V9 Rounded
124.45
PIC 9(3)V9 Rounded
3124.45
SIZE ERROR
Yes
Yes
No
Yes
Yes
No
Yes

A size error condition exists when, after decimal
point alignment, the result is truncated on either
the left or the right hand side.

If an arithmetic statement has a rounded phrase
then a size error only occurs if there is truncation
on the left hand side (most significant digits).
COMPUTE Verb
Syntax
COMPUTE identifier-1 . . . [ ROUNDED ]
= algebraic expression [ ON SIZE ERROR ]
imperative statement.
Example
COMPUTE VOLUME = ( 4 / 3) * ( 22 / 7 ) * R ** 3.
Note: If the ROUNDED and ON SIZE ERROR both
appear, then the ROUNDED option should precede the
ON SIZE ERROR.
The COMPUTE
COMPUTE  Identifier [ ROUNDED ] ... = ArithmeticExpression
  ON SIZE ERROR


 StatementBlock END - COMPUTE

NOT
ON
SIZE
ERROR



Precedence Rules.
Before
After
1.
**
=
POWER
NN
2.
*
/
=
=
MULTIPLY
DIVIDE
x
÷
3.
+
-
=
=
ADD
SUBTRACT
+
-
Compute IrishPrice = SterlingPrice / Rate * 100.
1000.50
156.25
87
179.59
156.25
87
Review
Features of COBOL.
General Coding and Format rules.
Language Fundamentals.
Input and Output verbs.
Arithmetic verbs.
Review questions
 If an entry must begin in area A ,it must begin in
Column number 8,9,10,11
 If an entry must begin in area B,it must begin in position
12 to 72 any where;
 Program-id is the paragraph name that appears in the
identification division
 The word rounded (precedes, follows) the ON SIZE
ERROR clause in an arithmetic statement precedes
Review questions
 A numeric literal in COBOL can have at most18 digits
 A Non numeric literal can have maximum
160 characters including spaces
 Indicate True or False
False
– A 01 level entry cannot have a picture class
– In COBOL a data name must contain at least 8
characters False
– A COBOL sentence consists of one or more than one
statement the last of which is terminated by a period
True
Any Questions
????
Thank you
Jyothi Sridhar Kini
E&R, Infosys
Mail-id: [email protected]
Phone: 52179