CS 313001Day 2

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CS 313-001 Day 2

• Chapter 1
• Introduction to COBOL and Program Development

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Todays Outline

• Handouts
• Roll
• CoE Labs Log in
• Lab Materials
• Chapter 1

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NOTE College of Engineering Laboratory Accounts 

• All students in CS 313 have an account on the CoE
  systems.  
• Your userid is ltfirst letter of first namegtltfirst
  letter of last namegtltlast four digits of
  UniversityWide IDgt. 
• So if your name was Jane Doe with a University
  wide ID of 12345678, your userid would be
  JD5678.  Your initial password is the same as
  your userid.  If anyone has a problem with your
  account, please go to MIB 325 for assistance.

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You will have mastered the material in Chapter 1
when you can

• Identify the advantages and disadvantages of
  COBOL
• Understand the difference between record
  input/output and stream input/output
• List the steps required by the programming
  process
• Name the logic structures used in a structured
  program

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• Describe the top-down design and top-down
  programming
• Name the four divisions of a COBOL program
• Specify the purpose of each COBOL division
• Identify valid COBOL words
• Describe the format of a line of COBOL source code

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COBOL is an acronym for

• COmmon
• Business
• Oriented
• Language

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COBOL

• Was first released in 1960 as a result of a joint
  effort of industry, major universities, and the
  United States government.
• The purpose of COBOL was to provide a high-level
  computer programming language for the business
  world.

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High-Level Language

• A high-level language is one that can be
  transferred easily from one working knowledge of
  a computers internal components.
• Examples
• COBOL, BASIC, Java, and Pascal are examples of
  high-level languages.

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Low-Level Language

• A low-level language is a programming language
  that requires knowledge of a computers internal
  components and cannot be transferred from one
  computer system to another.
• Examples
• Machine language and Assembly language are
  examples of a low-level language.

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Advantages of COBOL

• 1. COBOL has been widely accepted and used for
  more than 35 years.
• 2. Many businesses have a great investment in
  COBOL programs.
• 3. COBOL is machine independent.
• 4. COBOL is English-like and self- documenting.
• 5. COBOL is easy to read and understan.d

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Disadvantages of COBOL

• 1. COBOL programs tend to be very wordy.
• 2. COBOL programs require many pages of code to
  accomplish a task that requires only a page of
  two in another language.
• 3. COBOL tends to generate object code that is
  less efficient than the code generated by a
  low-level language.
• 4. COBOL is not designed to handle scientific
  or process control applications.

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Information Processing

• Stream Input/Output
• ACCEPT statement
• DISPLAY statement

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Basic Terms

• A field is a basic fact.
• Ex. Name, Address, CWID, Zip Code
• A record is a group of related fields.
• A file is a group of related records.

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Fields(Facts)
Records(Group of Fields)
Name John AdamsCredits 90Major Political
Science Name Amelia EarhartCredits 120Major
Aviation Name Orville WrightCredits 115Major
Engineering Name Georgia OKeeffeCredits 125
Major Art
Amelia Earhart 120 Aviation
Orville Wright 115 Engineering
Fields, Records, and Files
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Programming Specification

• Input,
• Processing and,
• Output requirements

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Input, Processing, and Output
INPUT
PROCESSING
OUTPUT
STUDENT NAME ORVILLE WRIGHT
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Blocked versus Unblocked Records
(a) Unblocked Records(One Logical Record per
Physical Record)
(b) Blocking Factor of Two(Two Logical Records
per Physical Record)
(b) Blocking Factor of Three(Three Logical
Records per Physical Record)
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Steps in the Programming Process

• 1. Understand the Problem
• 2. Design the Program
• 3. Code the Program
• 4. Test the Program
• 5. Document the Program