BU115: Computer Concepts Lecture Slides

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BU115 Computer ConceptsLecture Slides
Programming Languages
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Software Review

• SYSTEM
• What is the purpose of System software?
• What are the major components?
• What is multitasking?

• APPLICATION
• What is the purpose of Application software?
• What are the major types? Examples?
• What defines software compatibility?

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System Software Review

• QUIZ
• Chap 5A

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Software Programming Languages

• Bus 115

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Software Programming Languages
Week 3 Review
Learning Objectives
1. Explain the programming process 2. Identify
the major programming tools 3. Describe the
generations of programming languages 4. Compare
the language translators 5. Identify the major
programming languages
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Software Development
What is a computer program?

A series of instructions (algorithm) that direct
the computer in performing a specific task.
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Software Development
The Programming Process
A scientific methodology for designing and
developing programs.
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Software Development
Group Problem Solving
A Programming Project

• Your Sales Manager for a small computer company
  has told you that you need a program to handle
  sales
• What are the first steps in doing this project?

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Software Development
Program Development
1. Define the problem 2. Solve the problem 3.
Write your program 4. Test your program 5.
Implement your program (6. Maintain your
program)
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Software Development
The Programming Process
1. Problem Definition 2. Program Design 3.
Program Development (Coding) 4. Program
Testing 5. Program Implementation
(Documentation) 6. Program Maintenance
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Software Development

Problem Definition
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Software Development
1. Clarify Objectives Users
2. Specify Desired Output
Six Steps of the Problem Definition Stage
3. Specify Required Input
4. Specify Required Processing

5. Determine Feasibility
6. Document Analysis
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Software Development

Program Design
Problem Definition
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Software Development
Group Problem Solving
A Programming Project

• Your Sales Manager decides on a program to
  compute total sales for a series of items
• Develop in English the algorithm to compute the
  Total sales.

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Software Development
A Programming Project..

• What do you need to know?
• What output? (item, sales,)
• What input?
• (item, quantity and unit price)
• What processing?
• E.g. sales qty price
• discount 10 for orders of over 50.

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Software Development
A Programming Project..

• Sample Input
• Item Unit price Quantity
• CPU 375 10
• Drives 120 20
• RAM 256MB 80 55
• Power Supply 20 5
• Motherboard 425 15
• .

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Software Development
Program Design Tools

• Program Flowcharts
• Structure Charts
• Pseudocode

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Software Development
Program Flowchart
Terminal
Decision
Direction
Connector

Processing
Pre-Defined Process
Input/Output
Off-Page Connector
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Software Development

• Structure Chart

Sales Problem
Initialize
Calc Gross Sales
Calc Net Sales
Output Info
Input Data
Calc Discount
Accum. Totals
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• Pseudocode

• Sales Problem
• TotalSales 0
• Input Item, Price, Qty
• 3. GrossSales Price Qty
• 4. If Qty gt 50
• Then Disc GrossSales .1
• Else Disc 0
• 5. NetSales GrossSales - Disc
• TotalSales TotalSales NetSales
• Output Item, NetSales
• Output TotalSales

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Break Time
10 Minutes
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Software Development

• QUIZ
• Chap 10A

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Software Development

Program Coding
Program Design
Problem Definition
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Software Development

• Language selection
• Convert logic/pseudocode to program code
• Apply rules of language
• (syntax or grammar)

Program Coding

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Software Development
Program Testing

Program Coding
Program Design
Problem Definition
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Software Development
TESTING
Desk Checking
Debug

Real-World Data
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Software Development
TESTING

• Commercial Software
• Alpha Testing
• Beta Testing
• Gold

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Software Development
Document Install
Program Testing

Program Coding
Program Design
Problem Definition
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Software Development
DOCUMENTATION

User
Operator
Programmer
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Software Development
Document Install

• Implement programs
• Maintenance
• Fix errors
• Update

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Programming Languages
1st Generation
2nd Generation
Machine Language
3rd Generation
Assembly Language
4th Generation
High-Level Language
5th Generation
Very High-Level Language
Natural Language
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Decimal/Hex/Binary Numbers
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Machine Language
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Assembly Language
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High-Level Language
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High-Level Language
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Programming LanguagesComparison of Generations
1st Generation
5th Generation

• Binary, cryptic
• Procedural
• Faster
• More flexible
• More error-prone
• Difficult to learn/use

• English-like
• Non-procedural
• Slower
• Less flexible
• Less error-prone
• Easier to learn/use

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Advanced Programming

• Object-Oriented Programming (OOP)
• Visual Programming

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Programming Languages
Traditional Programming
Input
Step 1
Step 2
Step 3
Output
Step 4
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Programming Languages
Object-Oriented Programming
Data

• Library of objects
• Select objects to build application

Instructions
OBJECT
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Advanced Programming

• Object-Oriented Programming (OOP)
• Combines instructions and data into
  self-contained units (objects)
• Concepts
• Encapsulation object contains data instr
• Inheritance - inherits properties of class
• Polymorphism - many forms of same object

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Advanced Programming

• Visual Programming
• Extension of OOP
• Interface is created graphically (visually)
  using icons and mouse
• Faster development

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Programming Languages

• Traditional Languages
• Fortran
• COBOL
• PL/1
• BASIC
• C, C
• RPG

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Programming Languages

• Web Languages
• HTML (HyperText Markup Language)
• Text with embedded commands - for page links,
  graphics, etc.
• Used for Web pages
• Java language (like C)
• To create applications (applets) for web pages
• Very portable and scalable

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Review Programming Languages
Questions Answers
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Review Programming Languages

• Questions Answers
• Define
• a) Pseudocode
• An English-like representation of the logic of
  a program. It is used as a basis for coding
  programs.
• b) Structure Chart
• A graphic representation of the solution of a
  problem. It shows the problem sub-components in
  a hierarchical form.

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Review Programming Languages Questions Answers
2. Explain the purpose of language translators
and the difference between a compiler and an
interpreter. Language translators, convert the
program source code into machine language. The
compiler translates the entire program before
starting to execute the instructions. The
interpreter translates and executes each
instruction one at a time.
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Review Programming Languages Questions Answers
3. What is the difference between a procedural
language and an OOP language? Both are used to
develop software applications. With a procedural
language, you specify the algorithm (procedure)
to be applied to the input data to generate the
outcome In OOP, the instructions and data are
combined in a set of self-contained units
(objects), which are selected and used to build
the application.
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Software Review

• Software is the set of instructions to direct the
  computer (also documentation)
• Software falls into two main categories
• Systems - manage the system
• Application - applying the computer
• There is a methodology for developing software.

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