HP 3000 Manuals HP 3000 Manuals
Chapter 4 Describing and Referencing Data The data used by a COBOL program is defined and described in the DATA DIVISION, and referenced and operated upon in the PROCEDURE DIVISION. This data is stored in, read from, and written to files (collections of information) that reside on various peripheral devices. For instance, a payroll processing program might accept input from a file that contains wage and salary information for all employees on the company payroll; this program might also write new output to this same file during updating operations. Within a file, all information is organized into units of related data called logical records. These records are similar in form, purpose, and content. For example, in a payroll file, each logical record could contain the wage and salary data related to a particular employee. In other words, there would be one record for each employee. Within each record, individual elements of data, or groups of such elements, are called data items. As an example, a payroll record for an employee might contain the following data items: the employee's name, social security number, marital status, gross pay, tax exemptions, individual deductions, and net pay. The individual deductions data item might itself contain subordinate data items, such as federal income tax, state income tax, insurance premiums, bond payments, and charity contributions.