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Transcript of Jyothi Sridhar Kini E&R, Infosys Mail-id: [email protected]@infosys.com Phone: 52179...
Jyothi Sridhar KiniE&R, Infosys
Mail-id: [email protected]: 52179
Programming in COBOL-85
For IBM Mainframe System 390
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
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
History of COBOL
COBOL
COBOL is an acronym which stands forCOmmon 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
DIVISIONS
SECTIONS
PARAGRAPHS
SENTENCES
STATEMENTS
RESERVEDWORDS
USER DEFINEDWORDS
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 PROGRAM-ID 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 structureIDENTIFICATION DIVISION.PROGRAM-ID. PGM-NAME.[AUTHOR. YourName.]
IDENTIFICATION DIVISION.PROGRAM-ID. FIRSTPGM.AUTHOR. Michael Coughlan.
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...
IDENTIFICATION DIVISION. PROGRAM-ID. Member-name. ( Max 8 chars, letters & digits only )
AUTHOR. / Optional entry INSTALLATION. / Optional entryDATE-WRITTEN. / Optional entry DATE-COMPILED. / Optional entry
Is used to identify the program to the computer.
Is the least significant DIVISION of a COBOL program.
ENVIRONMENT DIVISION
The ENVIRONMENT DIVISION is totally optional unless you want to use files / specify special devices to the compiler in your program.
Is used to indicate the Specific Computers used to develop and execute the program.The general format of ED is
ENVIRONMENT DIVISION.CONFIGURATION SECTION.SOURCE-COMPUTER. VAX-6410.OBJECT-COMPUTER. IBM-ES9000.INPUT-OUTPUT SECTION.FILE-CONTROL.
SELECT EMPL-FILE ASSIGN TO DISC.
...
ENVIRONMENT DIVISION.CONFIGURATION SECTION.SOURCE-COMPUTER. VAX-6410.OBJECT-COMPUTER. IBM-ES9000.INPUT-OUTPUT SECTION.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
DATA DIVISION. / Optional entry FILE SECTION.FD filename. . . . . . . SD sortfile. . . . . . .WORKING-STORAGE SECTION.. . . . . . .
Is used to describe the structure of the fields, records, files and temporary variables used for calculations.
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 theinstructions 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 paragraph-
name 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 ADVANCINGACCEPT STUDENT-NAMEDISPLAY "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 TRUEEND-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
.
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
.
IDENTIFICATION DIVISION.PROGRAM-ID. SMALLPGM.
PROCEDURE DIVISION.A0000-DISPLAY-PARA. DISPLAY "I did it." STOP RUN
.
What is the model we have used to What is the model we have used to describe thedescribe theCOBOLCOBOL program structure? program structure?
TOP-DOWNTOP-DOWN
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
$ 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 72
80
Column numbers
* Area A Area B 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 commentsHyphen ( - ) indicates continuationSlash ( / ) 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
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.
Numeric literals
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.
Non-numeric literals
Literals
Figurative constants Meaning
ZERO(S) or ZEROES Represents the value 0, one ormore 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
Figurative constants
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
Is used to specify the the data hierarchy.
Level number
Level Number Purpose
01 Record description and independent items
02 to 49 Fields within records and sub items
66 RENAMES clause
77 Independent items
88 Condition names
Description of data names
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.
PICTURE clause
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.
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
STUDENT-DETAILS
WORKING-STORAGE SECTION.01 STUDENT-DETAILS PIC X(026).
WORKING-STORAGE SECTION.01 STUDENT-DETAILS PIC X(026).
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
STUDENT-DETAILS
STUDENT-NAMESTUDENT-NAME STUDENT-IDSTUDENT-ID COURSE-CODE GRANT GENDERCOURSE-CODE GRANT GENDER
Group Items/Records - Example
WORKING-STORAGE SECTION.01 STUDENT-DETAILS.
0202 STUDENT-NAMESTUDENT-NAME PIC X(010).PIC X(010).0202 STUDENT-IDSTUDENT-ID PIC 9(007).PIC 9(007).0202 COURSE-CODECOURSE-CODE PIC X(004).PIC X(004).0202 GRANTGRANT PIC 9(004).PIC 9(004).0202 GENDERGENDER PIC X(001).PIC X(001).
WORKING-STORAGE SECTION.01 STUDENT-DETAILS.
0202 STUDENT-NAMESTUDENT-NAME PIC X(010).PIC X(010).0202 STUDENT-IDSTUDENT-ID PIC 9(007).PIC 9(007).0202 COURSE-CODECOURSE-CODE PIC X(004).PIC X(004).0202 GRANTGRANT PIC 9(004).PIC 9(004).0202 GENDERGENDER PIC X(001).PIC X(001).
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
STUDENT-DETAILS
SURNAME INITIALS
WORKING-STORAGE SECTION.01 STUDENT-DETAILS.
0202 STUDENT-NAME.STUDENT-NAME.03 SURNAME03 SURNAME PIC X(008).PIC X(008).03 INITIALS03 INITIALS PIC X(002).PIC X(002).
0202 STUDENT-ID STUDENT-ID PIC 9(007).PIC 9(007).0202 COURSE-CODE COURSE-CODE PIC X(004).PIC X(004).0202 GRANT GRANT PIC 9(004).PIC 9(004).0202 GENDER GENDER PIC X(001).PIC X(001).
WORKING-STORAGE SECTION.01 STUDENT-DETAILS.
0202 STUDENT-NAME.STUDENT-NAME.03 SURNAME03 SURNAME PIC X(008).PIC X(008).03 INITIALS03 INITIALS PIC X(002).PIC X(002).
0202 STUDENT-ID STUDENT-ID PIC 9(007).PIC 9(007).0202 COURSE-CODE COURSE-CODE PIC X(004).PIC X(004).0202 GRANT GRANT PIC 9(004).PIC 9(004).0202 GENDER GENDER PIC X(001).PIC X(001).
STUDENT-NAMESTUDENT-NAME STUDENT-IDSTUDENT-ID COURSE-CODECOURSE-CODE GRANTGRANT GENDERGENDER
Group Items/Records
LEVEL Numbers & DATA hierarchy
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 is the relationship of the level numbers to one another, not the actual level numbers used.
01 STUDENT-DETAILS.02 STUDENT-NAME.
03 SURNAME PIC X(008).03 INITIALS PIC X(002).
02 STUDENT-ID PIC 9(007).02 COURSE-CODE PIC X(004).02 GRANT PIC 9(004).02 GENDER PIC X(001).
01 STUDENT-DETAILS.02 STUDENT-NAME.
03 SURNAME PIC X(008).03 INITIALS PIC X(002).
02 STUDENT-ID PIC 9(007).02 COURSE-CODE PIC X(004).02 GRANT PIC 9(004).02 GENDER PIC X(001).
01 STUDENT-DETAILS.05 STUDENT-NAME.
10 SURNAME PIC X(008).10 INITIALS PIC X(002).
05 STUDENT-ID PIC 9(007).05 COURSE-CODE PIC X(004).05 GRANT PIC 9(004).05 GENDER PIC X(001).
01 STUDENT-DETAILS.05 STUDENT-NAME.
10 SURNAME PIC X(008).10 INITIALS PIC X(002).
05 STUDENT-ID PIC 9(007).05 COURSE-CODE PIC X(004).05 GRANT PIC 9(004).05 GENDER 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.
Data movement verb.
Arithmetic Verbs.
Input / Output Verbs.
Sequence control verbs.
File handling verbs.
PROCEDURE DIVISION 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.
Input / Output Verbs
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
ADD Cash TO Total.BeforeBefore 3 1000AfterAfter
ADD Cash, 20 TO Total, Wage.Before Before 3 1000 100AfterAfter
ADD Cash, Total GIVING Result.BeforeBefore 3 1000 0015AfterAfter
ADD Males TO Females GIVING TotalStudents.Before Before 1500 0625 1234AfterAfter
ADD Cash TO Total.BeforeBefore 3 1000AfterAfter
ADD Cash, 20 TO Total, Wage.Before Before 3 1000 100AfterAfter
ADD Cash, Total GIVING Result.BeforeBefore 3 1000 0015AfterAfter
ADD Males TO Females GIVING TotalStudents.Before Before 1500 0625 1234AfterAfter
3 1003
3 1023 123
3 1000 1003
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 NUM-2.
(5) SUBTRACT NUM-1 FROM NUM-2 GIVING NUM-3.
SUBTRACT Examples
SUBTRACT Tax FROM GrossPay, Total.Before Before 120 4000 9120 AfterAfter
SUBTRACT Tax, 80 FROM Total.Before Before 100 480AfterAfter
SUBTRACT Tax FROM GrossPay GIVING NetPay.BeforeBefore 750 1000 0012AfterAfter
SUBTRACT Tax FROM GrossPay, Total.Before Before 120 4000 9120 AfterAfter
SUBTRACT Tax, 80 FROM Total.Before Before 100 480AfterAfter
SUBTRACT Tax FROM GrossPay GIVING NetPay.BeforeBefore 750 1000 0012AfterAfter
120 3880 9000
100 300
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 DIVIDEMULTIPLY Subs BY Members GIVING TotalSubs
ON SIZE ERROR DISPLAY "TotalSubs too small" END-MULTIPLY. Subs Members TotalSubsSubs Members TotalSubs
BeforeBefore 15.50 100 0123.45AfterAfter
MULTIPLY 10 BY Magnitude, Size.
BeforeBefore 355 125AfterAfter
DIVIDE Total BY Members GIVING Average ROUNDED.BeforeBefore 9234.55 100 1234.56AfterAfter
MULTIPLY Subs BY Members GIVING TotalSubs ON SIZE ERROR DISPLAY "TotalSubs too small" END-MULTIPLY. Subs Members TotalSubsSubs Members TotalSubs
BeforeBefore 15.50 100 0123.45AfterAfter
MULTIPLY 10 BY Magnitude, Size.
BeforeBefore 355 125AfterAfter
DIVIDE Total BY Members GIVING Average ROUNDED.BeforeBefore 9234.55 100 1234.56AfterAfter
15.50 100 1550.00
3550 1250
9234.55 100 92.35
ROUNDED Option
Syntax
Arithmetic statement [ ROUNDED ].
Examples
(1) ADD NUM-1, NUM-2, NUM-3 GIVING NUM-4ROUNDED.
(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
PIC 9(3). 123.25
123.2 123.3
123 123
The The ROUNDEDROUNDED option takes effect when, after option takes effect when, after decimal point alignment, the result calculated decimal point alignment, the result calculated must be truncated on the right hand side. must be truncated on the right hand side.
The option adds 1 to the receiving item when the The option adds 1 to the receiving item when the leftmost truncated digit has an absolute value of 5 leftmost truncated digit has an absolute value of 5 or greater.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.
A size error condition exists when, after decimal A size error condition exists when, after decimal point alignment, the result is truncated on either point alignment, the result is truncated on either the the leftleft or the or the rightright hand side.hand side.
If an arithmetic statement has a rounded phrase If an arithmetic statement has a rounded phrase then a size error only occurs if there is truncation then a size error only occurs if there is truncation on the on the leftleft hand side (most significant digits). hand side (most significant digits).
Receiving Field Actual Result SIZE ERROR
PIC 9(3)V9. 245.96
PIC 9(3)V9. 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
On size error option
Yes
Yes
No
Yes
Yes
No
Yes
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.
Compute IrishPrice = SterlingPrice / Rate * 100.Before Before 1000.50 156.25 87 AfterAfter
Compute IrishPrice = SterlingPrice / Rate * 100.Before Before 1000.50 156.25 87 AfterAfter 179.59 156.25 87
The COMPUTE
COMPUTE Identifier [ ROUNDED ] . . . = ArithmeticExpression
ON SIZE ERROR
NOT ON SIZE ERROR StatementBlock END - COMPUTE
Precedence Rules.Precedence Rules.1.1. **** = POWER NN
2.2. ** = MULTIPLY x// = DIVIDE ÷
3.3. ++ = ADD +-- = SUBTRACT -
Precedence Rules.Precedence Rules.1.1. **** = POWER NN
2.2. ** = MULTIPLY x// = DIVIDE ÷
3.3. ++ = ADD +-- = SUBTRACT -
ReviewFeatures 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
If an entry must begin in area B,it must begin in position
Program-id is the paragraph name that appears in the
The word rounded (precedes, follows) the ON SIZE ERROR clause in an arithmetic statement
Column number 8,9,10,11
12 to 72 any where;
identification division
precedes
Review questions
A numeric literal in COBOL can have at most A Non numeric literal can have maximum
Indicate True or False– A 01 level entry cannot have a picture class – In COBOL a data name must contain at least 8
characters – A COBOL sentence consists of one or more than one
statement the last of which is terminated by a period
18 digits
160 characters including spaces
False
False
True
Any Questions ????