COBOL (Common Business Oriented Language) is a programming language specifically designed for business applications. COBOL programs consist of two main parts:
Data Division and Procedure Division. However, there's an additional concept that comes into play - COBOL Copybook. In this article, we'll explore the differences between COBOL Copybook and COBOL Data Division, and how we define and use each of them in a mainframe application.
COBOL Copybook is a file that consists of the description of data items that are used in a COBOL program. It is an external file used to define data structures, record layouts, and data constants that are used in the program. The data items defined in the copybook can be used in many programs, thus simplifying the process of defining and maintaining data item definitions. Copybooks can be used to define a structure or record definition that is used across multiple programs.
COBOL Data Division defines the data structures and record layouts that are used in the program itself. It consists of sections, which are further divided into paragraphs, which contain data item definitions. The data items are defined using a set of reserved words, such as PIC (Picture), LEVEL, OCCURS, and REDEFINES. The Data Division describes the data used by the COBOL program itself.
The use of COBOL Copybook and COBOL Data Division in a Mainframe application is an important aspect of the development process. Copybooks are typically used to define common data structures that are used across multiple programs. This allows for the reuse of data structures and reduces the amount of code that needs to be written. Data Division, on the other hand, is used to define data structures that are specific to the program itself.
For example, if we have a program that processes customer transactions, the data items specific to that program would be defined in the Data Division of that program. However, if we had other programs that also needed to access the same customer information, we could define the common data items, such as customer name and address, in a Copybook, which would be accessed by each program that required the information.
So, to summarize it, COBOL Copybook and COBOL Data Division both play a vital role in creating and maintaining Mainframe applications in TCS. Copybooks help define a structure or record layout that is used across multiple programs, thus simplifying the process of defining and maintaining data item definitions. Data Division describes the data used by the COBOL program itself.