1. Developing Applications
Notes for Chapter 14
Digital Domain, 2 ed

2. Programming Languages
Programs consist of sequence of instructions performed within the fetch—execute cycle
All instructions must be in a particular processor’s machine language before that processor can execute them
machine languages are expressed in binary codes
assembly languages are symbolic versions of machine languages
Higher level languages allow programmers to express a process in a more abstract form (closer to the actual problem domain)
these high-level languages must be translated into machine languages
both compiler and interpreter software can be used to accomplish this translation

3. Programming Languages (cont’d)
Programs often employ variables and functions to accomplish their tasks
Conditional statements alter the flow of control within the program sequence
allow the program to “make decision”
move to different sequences of instructions based on Boolean conditions (conditions that can be true or false)

4. Scripting Languages Scripting languages are interpreted languages
Very useful for Web-related programming tasks
add interactivity to Web pages
enable interaction with backend databases

5. The Software Development Cycle
Analyze and understand the problem
Devise a plan to solve the problem
Create an executable program that implements the plan
Test and correct the program

6. Program Plans as Algorithms
Program plans are expressed as algorithms
what information is needed?
what events are needed to process the information?
how must these events be sequenced?
Algorithms may be expressed using
flow charts
pseudocoding
Translating an algorithm to an executable program is called coding

7. Testing and Software Complexity
Testing involves running a program with the goal of finding any errors (sometimes called bugs) so they can be corrected
Large programs are very complex
testing can rarely uncover all bugs
beta testing allows program users to help uncover additional errors after initial testing is completed
Testing is part of a larger process known as software quality assurance

8. Software Development is a Team Effort
Systems analysts – planning and design
Project manager – oversee the schedule and budget
Programmers – work in teams to complete the coding
Quality assurance – testing

9. Programming Paradigms
A programming paradigm defines the basic model by which a language expresses a process
imperative procedural paradigm
uses modules called procedures or functions
examples: Pascal, BASIC, FORTRAN, COBOL, C, and ADA
object-oriented paradigm
objects encapsulate both data and process
objects have attributes (data)
objects have associated methods (process)
most scripting languages use this paradigm
examples: Java, C++, JavaScript, VBScript, and Visual Basic

10. Programming Paradigms (cont’d)
nonprocedural paradigm
often used in artificial intelligence (AI) applications
examples: Prolog, LISP, and FP

11. Other Programming Languages
End-user languages
Languages for Internet applications
scripting languages
event-driven programming
Languages for extending and integrating applications
visual programming (Visual BASIC)
AppleScript
Languages for specialized applications
Director/Lingo
Flash/ActionScript

12. Summary
Programs consist of sequence of instructions performed within the fetch—execute cycle
All instructions must be in a particular processor’s machine language before that processor can execute them
Higher level languages allow programmers to express a process in a more abstract form (closer to the actual problem domain)
The software development cycle consists of:
Analyze and understand the problem
Devise a plan to solve the problem
Create an executable program that implements the plan
Test and correct the program

13. Summary (cont’d) Software development is a team effort
Systems analysts – planning and design
Project manager – oversee the schedule and budget
Programmers – work in teams to complete the coding
Quality assurance – testing
There are number of programming paradigms
imperative procedural paradigm
object-oriented paradigm
nonprocedural paradigm