COBOL programming site with a full COBOL course as well as lectures, tutorials, programming exercises, and over 50 example COBOL programs. This course is for programmers who’s COBOL is a bit rusty. Topics include a refresher of the major divisions of a COBOL program, Working-Storage data types. Cobol refresher – WSVAR PIC COMP SYNC. Multiple level inFile section is an example for implicit RECORDS Clause As general rule LABEL.
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Commands to quickly add names to your personal lists. The profile command is used either to specify to the system certain user characteristics which are to be used to control the flow of retresher to and from the terminal or to list the user profile. The user profile is retained throughout each terminal session unless the user wishes to change it by issuing the profile command again and specifying the appropriate operands.
The Clipboard can then be browsed or deleted. Displays the screen name of the Top Left corner.
A Program is a set of instructions that enables a computer to process data, there are two types of computer programs which are 1- Operating system programs, which control the overall operation of the system and 2- Applications programs, it is the actual program tasks required by the users. The term used to describe all type of programs is called software in general application program reads inputprocess it, and produce information or out put the user neads. A set of computerized business procedures in an application area is called information systems.
Design the program planning tools. Code and enter the program. As the the expanded acronym indicates, COBOL is designed for developing business, typically file-oriented, applications. It is not designed for writing systems programs.
This is the first division and the program is identified here. All other paragraphs are optional and used for documentation. Security does not pertain to the operating system security, but the information that is passed to the user of the program about the security features of the program.
It supplies information about the hardware or computer equipment to be used on the program. Data division is used to define the data that need to be accessed by the program. It has three sections.
Literal is a constant and it can be numeric or non-numeric. Numeric literal can hold 18 digits and non-numeric literal can hold characters in it. COBOL74 supports characters only 3.
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Literal stored in a named memory location is called as variable or identifier. WS-VAR1 is a identifier or variable.
It specifies the hierarchy of data within a record. It can take a value from the set of integers between or from one of the special level-numbers 66 77 Variable name can have characters with at least one alphabet in it.
Hyphen is the only allowed special character but it cannot be first or last letter of the name. Name should be unique within the record. If two variables with same name are there, then use OF qualifier of high level grouping to refer a variable uniquely.
Most significant bit is ON if the number is negative. PIC Clause should not be specified. Two digits are stored in each byte. Last nibble is for sign.
F for unsigned positive, C for signed positive and D for signed negative Formula for Bytes: Value of item must not exceed picture size. It cannot be specified for the items whose size is variable. It is stored along with last digit. SYNC clause does this but it may introduce slack bytes unused bytes before the binary item.
WS-VAR2 is expected to start at second byte. As the comp item in the example needs one word and it is coded with SYNC clause, it will start only at the next word boundary that is 4th byte. Redefining declaration should immediately follow the redefined item and should be done at the same level. Multiple redefinitions are possible. Size of redefined and redefining need not be the same.
It is used for regrouping of elementary data items in a record.
It should be declared at 66 level. It need not immediately follows the data item, which is being renamed. A condition name specifies the value that a field can contain and used as abbreviation in condition checking. This clause can be specified with alphanumeric and alphabetic items for right justification. It cannot be used with 66 and 88 level items. OCCURS Clause is used to allocate physically contiguous memory locations to store the table values and access them with subscript or index.
Detail explanation is given in Table Handling section. It is used to access the data that are external to the program. Linkage section MUST be coded with a half word binary field, prior to actual field. If length field is not coded, the first two bytes of the field coded in the linkage section will be filled with length and so there are chances of 2 bytes data truncation in the actual field. This is the last division and business logic is coded here.
It has user-defined sections and paragraphs. Section name should be unique within the program and paragraph name should be unique within the section. Procedure division statements are broadly classified into following categories. It is used to transfer data between internal storage areas defined in either file section or working storage section.
A numeric or numeric-edited item receives data in such a way that the decimal point is aligned first and then filling of the receiving field takes place. Unfilled positions are filled with zero. Zero suppression or insertion of editing symbols takes places according to the rules of editing pictures.
Alphabetic, alphanumeric or alphanumeric-edited data field receives the data from left to right. Any unfilled field of the receiving filed is filled with spaces. When the length of receiving field is shorter than that of sending field, then receiving field accepts characters from left to right until it is filled. The unaccomodated characters on the right of the sending field are truncated. When an alphanumeric field is moved to a numeric or numeric-edited field, the item is moved as if it were in an unsigned numeric integer mode.
When MOVE statement is used to move information at group level, the movement of data takes place as if both sending and receiving fields are specified as alphanumeric items. This is regardless of the description of the elementary items constituting the group item. To retain the values of operands participating in the operation. The resultant value of operation exceeds any of the operand size.
It is usually coded after the field rdfresher be rounded. We can use arithmetic symbols than keywords and so it is simple and easy to code. Left to right refdesher 1. Multiplication and Division 4. Addition and Subtraction Caution: All arithmetic operators have their own explicit scope terminators. It is suggested cobo, use them.
It is used to display data. It returns control back to OS. It returns control back to main program. It just gives the control back from where it received the control. There are two famous Collating Sequence available in computers. The result of arithmetic and alphabetic comparison would be same in both collating sequences whereas the same is not true for alphanumeric comparison. The syntax of IF statement is given below: THEN is a noise word and it is optional.
This rule can be overridden by using parentheses. If you forgot the difference between statement and sentence, refer the first page. In compound conditions, it is not always necessary to specify both operands for each condition.
SIGN test is used to check the sign of a data item. It can be used in the following way. Any simple, relational, class, sign rferesher can be negated using NOT. Any complex condition can be given in the WHEN clause.
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Break statement is not needed, as it is so in other languages. It executes all refresner instructions coded in PARA-1 and then transfers the control to the next instruction in sequence. This is equal to DO. END structure of other languages. The identifiers used in the UNTIL condition s must be altered within the paragraph s being performed; otherwise the paragraphs will be performed indefinitely.
If the condition in the UNTIL clause is met at first time of execution, then named paragraph s will not be executed at all.