## CHAPTER 0 

## Introduction 

## O.A. An Overview of Pascal Programs 

Much of the following text assumes that you, the reader, have a minimal grasp of computer terminology and a "feeling" for the structure of a program. The purpose of this section is to spark your intuition. 

An algorithm or computer program consists of two essential parts, a description of actions that are to be performed, and a description of the data, that are manipulated by these actions. Actions are described by so-called statements, and data are described by s<r-Called declarations and definitions. 

The program is divided into a heading and a body, called a block. The heading gives the program a name and lists its parameters. These are (file) variables and represent the arguments and results of the computation. The block consists of six sections, where any except the last may be empty. They must appear in the order given in the definition for a block: 

Block = LabeLDeclarationPart C onstantDefinitionP art TypeDejinitionPart VariableDeclarationP art ProcedureAndFunctionDeclarationPart StatementPart . 

