How To Understand Programming Languages And Programming Languages

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Chapter 13 Programming Languages and Program

Development

Chapter 13 Objectives

Next Describe various ways to develop Web pages including HTML, scripting languages, DHTML, XML, WML, and Web page authoring software Describe various ways to develop Web pages including HTML, scripting languages, DHTML, XML, WML, and Web page authoring software Differentiate between machine

and assembly languages Differentiate between machine

and assembly languages

Identify and discuss the purpose of procedural programming languages Identify and discuss the purpose of procedural programming languages

Discuss the advantages and uses of visual programming languages Discuss the advantages and uses of

visual programming languages

Identify and discuss the characteristics of object-oriented programming languages Identify and discuss the characteristics of object-oriented programming languages

Identify the uses of various nonprocedural languages and tools Identify the uses of various nonprocedural

languages and tools

Identify the uses of popular multimedia authoring programs Identify the uses of popular multimedia

authoring programs

List the six steps in the program development cycle List the six steps in the program development cycle

Differentiate between structured design and object-oriented design Differentiate between structured design and

object-oriented design

Explain the basic control structures used in designing solutions to programming problems Explain the basic control structures used in designing solutions to programming problems

Computer Programs and Programming Languages What is a computer program?

p. 664 Fig. 13-1 Next

Ø Set of instructions that directs computer to perform tasks

§ Programming language— used to write instructions

Click to view video Click to view animation

Computer Programs and Programming Languages What are low-level languages and high-level languages?

p. 664 Next

High-level language High-level language Low-level

language Low-level

language

Machine-dependent runs only on one type of computer

Machine-dependent

runs only on one type of computer Often machine-independent can run on many different

types of computers Often machine-independent

can run on many different types of computers Machine and assembly languages

are low-level Machine and assembly languages

are low-level

Low-Level Languages

What is machine language?

p. 665 Fig. 13-2 Next

Ø Only language computer directly recognizes

Click to view animation

Low-Level Languages

What is assembly language ?

p. 666 Fig. 13-3 Next

Ø Instructions made up of symbolic instruction codes, meaningful abbreviations and codes Ø Source program contains

code to be converted to

machine language

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Procedural Languages

What is a procedural language?

p. 666 Next

Most widely used are BASIC, COBOL, and C Uses series of English-like words to write instructions

Often called third third- -generation generation language (3GL) language (3GL) Programmer writes instructions that tell computer what to accomplish

and how to do it

Click to view animation

Procedural Languages

What is a compiler?

p. 667 Fig. 13-4 Next

Ø Program that converts entire source program into machine language before executing it

Procedural Languages

What is an interpreter?

p. 667 Fig. 13-5 Next

Ø Program that translates and executes one program code statement at a time

Ø Does not produce object program

Procedural Languages

What is BASIC?

p. 668 Fig. 13-6 Next

Ø Designed for use as simple, interactive problem-solving language

Ø Beginner’s All-purpose Symbolic Instruction Code

Procedural Languages

What is COBOL?

p. 668 Fig. 13-7 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click COBOL below Chapter 13

Ø Designed for business applications

Ø English-like statements make code easy to read, write, and maintain

Ø COmmon

Business-Oriented Language

Procedural Languages

What is C?

p. 669 Fig. 13-8 Next

Ø Powerful language originally designed to write system software

Ø Requires professional programming skills

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Object-Oriented Programming Languages

What is an object-oriented programming (OOP) language?

p. 669 Next

Used to implement object-oriented

design

Major benefit is ability to reuse existing

objects

Event-driven—

checks for and responds to set of events

C++ and Java are complete object-oriented

languages

Objectis

item that contains data and procedures that act on data

Eventis action to which program responds

Object-Oriented Programming Languages

What is C++?

p. 670 Fig. 13-9 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click C++ below Chapter 13

Ø Includes all elements of C, plus additional features for working with object-oriented concepts Ø Used to develop

database and Web applications

Object-Oriented Programming Languages

What is Java?

p. 670 Fig. 13-10 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click Java below Chapter 13

Ø Developed by Sun Microsystems Ø Similar to C++ but

uses just-in-time (JIT) compiler to convert source code into machine code

Click to view video

Object-Oriented Programming Languages

What is a visual programming language?

p. 671 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click RAD below Chapter 13

Programmer writes and implements program in segments Visual programming

environment (VPE) allows developers to drag and drop objects

to build programs

Often used in Often used in RAD RAD

(rapid application (rapid application development) development) environment environment

Sometimes called Sometimes called fifth

fifth- -generation language generation language Provides visual or Provides visual or graphical interface for graphical interface for creating source code creating source code

Object-Oriented Programming Languages

What is Visual Studio .NET 2003?

p. 672 Fig. 13-11 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click Visual Studio .NET 2003 below Chapter 13

Ø

Suite of visual programming languages and RAD tools

Ø

.NET is set of technologies that allows program to run on Interne t

Ø Visual Basic .NET 2003

is used to build complex object-based programs

Step 1. The

programmer designs the user interface.

Step 2.The programmer assigns properties to each object on the form.

Step 4.The programmer

Step 3.The programmer writes code to define the action of each command button.

Object-Oriented Programming Languages

What is Delphi?

p. 673 Fig. 13-12 Next

Ø Powerful visual programming tool

Ø Ideal for large-scale enterprise and Web applications

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Object-Oriented Programming Languages

What is PowerBuilder?

p. 674 Fig. 13-13 Next

Ø Another powerful visual programming tool Ø Best suited for Web-based and large-scale

object-oriented applications

Nonprocedural Languages and Program Development Tools

Ø What are nonprocedural languages and program development tools?

p. 674 Next

Nonprocedural Language The programmer writes English- like instructions or interacts with a visual environment to retrieve data from files or a database

Program Development Tools User-friendly programs designed

to assist both programmers and users in creating programs Program Development

Tools User-friendly programs designed

to assist both programmers and users in creating programs

Nonprocedural Languages and Program Development Tools

What is RPG (Report Program Generator)?

p. 674 Fig. 13-14 Next

Ø Nonprocedural language used for generating reports, performing computations, and updating files

Nonprocedural Languages and Program Development Tools

What is a fourth-generation language (4GL)?

p. 675 Fig. 13-15 Next

Ø

Nonprocedural language that allows access to data in database

Ø

Popular 4GL is SQL, query language that allows users to manage data in relational DBMS

Nonprocedural Languages and Program Development Tools What is an application generator?

p. 675 Fig. 13-16 Next

Ø

Program that creates source code or machine code from specification

Ø

Consists of report writer, form, and menu generator

§ Form provides areas for entering data

Nonprocedural Languages and Program Development Tools

What is Visual Basic for Applications (VBA)?

p. 676 Fig. 13-17 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click Macros below Chapter 13

Ø Macro programming language

§ Macro— series of statements used to automate tasks

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Web Page Development

What is HTML (Hypertext Markup Language)?

p. 678 Fig. 13-18 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click HTML below Chapter 13

Ø Used to create Web pages

Web Page Development

How are special effects and interactive elements added to a Web page?

p. 679 Next

Counter Counter tracks number of visitors to

Web site

Image map Image map graphic image that

points to URL Script

Script interpreted program that runs on client

Applet Applet usually runs on client, but is compiled

Processing Processing form form collects data from visitors

to Web site Servlet Servlet applet that

runs on server

ActiveX ActiveX control control small program

that runs on client

Web Page Development

What is the common gateway interface (CGI)?

p. 680 Fig. 3-19 Next

Ø

Communications standard that defines how Web server communicates with outside sources

Step 3. When the user submits a request, it is sent to the CGI program.

The CGI program contacts the database and requests information for the user. In this case, it looks for a movie titled The Wizard of Oz.

Step 1. The programmer stores the CGI program in a special folder on the Web server such as /cgi-bin.

Database

§

CGI script— program that manages sending and receiving across CGI

Step 2. The Webmaster creates a link between the CGI program and Web page. When a user displays the Web page, the CGI program automatically starts.

Step 4. The CGI program receives information from the database, assembles it in an HTML format, and sends it to the user ’s Web browser.

Web Page Development

What is a scripting language?

p. 681 Fig. 13-20 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click Scripting Languages below Chapter 13

Ø Typically easy to learn and use

§ JavaScript— adds

dynamic content and interactive elements to Web page

§ VBScript (Visual Basic,

Scripting Edition)— adds intelligence and interactivity to Web page

§ Perl

(Practical Extraction and Report Language)—

has powerful text processing capabilities

Web Page Development

What is dynamic HTML (DHTML)?

p. 682 Fig. 13-21 Next

Ø Allows developers to include more graphical interest and interactivity in Web page

Web Page Development

What are XHTML, XML, and WML?

p. 682 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click XML below Chapter 13

XHTML (Extensible HTML)

enables Web sites to be displayed

more easily on microbrowsers

XML

(Extensible Markup Language)

allows developers to create customized tags

WML

(Wireless Markup Language)

allows developers to design pages

specifically for microbrowsers

Includes features of HTML and XML

Useswireless application protocol (WAP),

standard that specifies how wireless devices communicate with Web Server sends entire record to

client, enabling client to do much of processing without going back to server

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FrontPage

FrontPage

2003

2003

Flash

Flash

MX

Web Page Development

What is Web page authoring software?

p. 683 Next

Ø Creates sophisticated Web pages without using HTML Ø Generates HTML

Dreamweaver

Dreamweaver

MX

Multimedia Program Development

What is multimedia authoring software?

p. 684 Fig. 13-22 Next

Ø

Combines text, graphics, animation, audio, and video into interactive presentation

Ø

Used for computer-

based training (CBT) and Web- based training (WBT)

Ø

Software includes Toolbook, Authorware, and Director

Other Programming Languages

What are other available programming languages?

p. 685 Next

ALGOL ALGOL ALGOL ADA ADA

ADA APL APL APL

FORTH FORTH

FORTH FORTRAN FORTRAN FORTRAN HYPERTALK HYPERTALK HYPERTALK LISP LISP LISP

LOGO LOGO

LOGO MODULA MODULA- MODULA-2 -2 2 PASCAL PASCAL PASCAL

PILOT PILOT

PILOT PL/I PL/I PL/I PROLOG PROLOG PROLOG SMALLTALK SMALLTALK SMALLTALK

The Program Development Cycle

What is the program development cycle?

p. 686 Fig. 13-24 Next

Ø Steps programmers use to build computer programs

§ Programming team— Group of programmers working on program

Step 1 — Analyze Requirements

What is involved in analyzing the requirements?

p. 687 Fig. 13-25 Next

1. Review requirements

2. Meet with systems analyst and users 3. Identify input, output, processing, and data

components

§ IPO chart—

Identifies program’s inputs, outputs, and processing steps

Programmer Programmer begins with general begins with general design and moves toward design and moves toward

detailed design detailed design

Step 2 — Design Solution

What is involved in designing the solution?

p. 688 Next

Object Object--oriented oriented

design design

Structured Structured design design, sometimes , sometimes called

called toptop--down designdown design

Two

Two approaches approaches Devise

Devise

solution

algorithm

algorithm, ,

step

step- -by by- -step step

procedure to

solve problem

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Step 2 — Design Solution

What is a hierarchy chart?

p. 688 Fig. 13-26 Next

Ø Shows program modules graphically Ø Also called structure chart

Step 2 — Design Solution

What is object-oriented (OO) design?

p. 689 Fig. 13-27 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click Object-Oriented Design below Chapter 13

Ø Programmer packages data and procedure into single unit, an object

§ Objects are grouped into classes

§ Class diagram represents hierarchical relationships of classes graphically

Step 2 — Design Solution

What is a sequence control structure?

p. 690 Fig. 13-28 Next

Ø Control structure that shows actions following each other in order

§ Control structure depicts logical order of program instructions

Step 2 — Design Solution

What is a selection control structure?

p. 690 Fig. 13-29 Next

Ø Tells program which action to take, based on a certain condition

Ø Two types

§ Case control structure

§ If-then-else control structure— yields one of two possibilities:

true or false

Step 2 — Design Solution

What is a case control structure?

p. 690 Fig. 13-30 Next

Ø Yields one of three or more possibilities

Step 2 — Design Solution

What is a repetition control structure?

p. 691 Figs. 13-31–13- 32 Next

Ø Enables program to perform one or more actions repeatedly

§ Do-while control structure— repeats as long as condition is true

§ Do-until control structure— repeats until condition is true

Do -While Control Structure Do -Until Control Structure

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Step 2 — Design Solution

What is a program flowchart?

p. 692 Fig. 13-33 Next

Ø Graphically shows logic in solution algorithm

Step 2 — Design Solution

What is an example of a flowchart?

p. 692 Fig. 13-34 Next

Step 2 — Design Solution

What is flowcharting software?

p. 692 Fig. 13-35 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click Flowcharting Software below Chapter 13

Ø Used by programmers to develop flowcharts

Step 2 — Design Solution

What is pseudocode?

p. 694 Fig. 13-36 Next

Ø Uses condensed form of English to convey program logic

Step 3 — Validate Design

What is involved in validating the design?

p. 694 Next

Check program design for accuracy

Logic error design flaw that causes inaccurate results

Test data sample data that mimics real data that program will process

Programmer checks logic for correctness and attempts to uncover

logic errors

Desk check programmers use test data to step through logic

Structured walkthrough programmer explains logic of algorithm while programming team steps

through program logic

Step 4 — Implement Design

What is implementation?

p. 695 Fig. 13-37 Next

Click to view Web Link, click Chapter 13, Click Web Link from left navigation, then click Extreme Programming below Chapter 13

Ø

Writing the code that translates the design into a program

§ Syntax— rules that specify how to write instructions

§ Comments— program documentation

Ø

Extreme programming (XP)— coding and testing as soon as

requirements are defined

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Step 5 — Test Solution

What is involved in testing the solution?

p. 696 Next

Ensure program runs correctly Ensure program runs correctly

and is error free and is error free

Debugging

Debugging— — locating and locating and correcting syntax and logic correcting syntax and logic

errors, or errors, or bugs bugs

Test copy of program, Test copy of program, called

called betabeta, sometimes , sometimes used to find bugs used to find bugs