COP 2121 Introduction

Course Objectives

• Understand how to develop and implement a program in the COBOL language
• Understand various forms of data representation and structures supported by the COBOL language
• Understand the syntax and semantics of the COBOL language
• Understand the appropriate applications (typically business) of the COBOL language

Introduction

• What is a computer program?
  • A set of instructions that enables a computer to do some task
• Two types of computer programs
  • Operating system programs - control overall operations of computer
  • Applications programs - perform tasks required by users

Applications Programs

• Written by applications programmer
• May provide quick solution to one-time prblem
  • Displaying average grade for set of exam scores
• Or may be run on regularly scheduled basis
  • Program to print student transcripts each semester
• Customized
  • Written for specific users like doctors, car dealerships
  • Necessary if user has special requirements
• Packages
  • Written for general user who needs program to perform standard tasks
    • Standard tasks include budgeting, scheduling payroll, etc.
  • Cheaper, easier than writing customized program

Program Languages

• Machine Language
  • Only language computer understands
  • All programs executed on computer must be in machine language
  • Machine language programs are difficult to write
• Symbolic language (like COBOL)
  • English-like languages used to write programs
  • Easier than writing programs in machine language
  • Must be translated or compiled into machine language to run on computer

COBOL

• Standard language
• English-like, high-level language
  • Relatively easy to read/write/understand
• Business-oriented language
  • Easy to produce nice looking reports
  • File processing capabilities
  • Batch and/or interactive
• Structured programming

History of COBOL

• Developed in 1959 by CODASYL committee
  • as standard language to meet needs of business
• CODASYL (COnference on DAta SYstems Languages) committee
  • Convened by Department of Defense
  • Included representative from academia, business, and computer manufacturers

Standard Versions of COBOL

• 1960's - wide variations of COBOL compilers
• 1968 - First COBOL standard set by American National Standards Institute (ANSI)
• 1974 - Second ANSI standard to make COBOL more efficient, standardized
• 1985 - This ANSI standard incorporated structured programming techniques

Current and future standards

• 1985 currently the most widely used
• 2008 is next standard
  • Approval expected in 2008 or so
  • Information on 2008 COBOL standard at ANSI
• Likely to remain an important language

Use of COBOL

• About 200 billion lines of COBOL source code in use
  • COBOL applications manage 85% of business data
• 5 Billion new lines added each year
• Used by 42.7% of application programmers in medium to large U.S. companies

What this course will teach

• How to design and develop application programs using COBOL language
  • Understand the syntax and semantics of the COBOL language
  • Understand various forms of data representation and structures supported by the COBOL language

Program Development Process

1. Determine program specification
2. Design program using program planning tools
3. Code and enter program
4. Compile program
5. Test program
6. Document program