Computers: Understanding Technology, 3e

1
Chapter 12
Programming Concepts and Languages
2
Presentation Overview

• Programming Concepts
• Problem-Solving Techniques
• The Evolution of Programming Approaches
• Programming Development and Documentation Tools
• Programming Errors
• The Software Development Life Cycle
• Major Programming Languages

3
Programming Concepts

• What makes up a programming language?

4
Programming Concepts

• What makes up a programming language?
• Program instructions telling a computer how to
  perform tasks

5
Programming Concepts

• What makes up a programming language?
• Program instructions telling a computer how to
  perform tasks
• Programming languages languages that
  communicate with the computer to create programs

6
Programming Concepts

• What makes up a programming language?
• Program instructions telling a computer how to
  perform tasks
• Programming languages languages that
  communicate with the computer to create programs
• Source code text files that make up a
  programming language

7
Programming Concepts

• What makes up a programming language?
• Program instructions telling a computer how to
  perform tasks
• Programming languages languages that
  communicate with the computer to create programs
• Source code text files that make up a
  programming language
• Four main computer language programming elements
  are variables, executable statements, looping,
  and decision statements.

8
Programming Concepts

• High-Level versus Low-Level Languages

9
Programming Concepts

• High-Level versus Low-Level Languages
• Low-level language (machine code) is a binary
  language consisting of 1s and 0s runs faster
  and takes up less disk space.

10
Programming Concepts

• High-Level versus Low-Level Languages
• Low-level language (machine code) is a binary
  language consisting of 1s and 0s runs faster
  and takes up less disk space.
• High-level language is similar to natural
  languages, making it easier to learn and use.

11
Programming Concepts

• Each generation of programs builds on the
  contributions of the group of languages that
  preceded it.

12
Programming Concepts

• Classic Programming Elements

13
Programming Concepts

• Classic Programming Elements
• Variable data value stored in computer memory

14
Programming Concepts

• Classic Programming Elements
• Variable data value stored in computer memory
• Executable statement performs an action and then
  proceeds to the next statement in sequence

15
Programming Concepts

• Classic Programming Elements
• Variable data value stored in computer memory
• Executable statement performs an action and then
  proceeds to the next statement in sequence
• Looping allows a program to return to a
  previously executed instruction and repeat it

16
Programming Concepts

• Classic Programming Elements
• Variable data value stored in computer memory
• Executable statement performs an action and then
  proceeds to the next statement in sequence
• Looping allows a program to return to a
  previously executed instruction and repeat it
• Decision statement point in a program where
  different actions may be performed depending on
  specific conditions

17
Programming Concepts

• Looping allows a computer program to
  continuously repeat the same steps, such as a
  program designed to direct a traffic light to
  display yellow, red, and green lights at a
  consistent rate.

18
Programming Concepts

• Using an if-then statement based on a particular
  action, such as pushing the crosswalk button, a
  program can interrupt the looping pattern, making
  the program more useful.

19
Problem-Solving Techniques

• Top-down design approach helps programmers break
  a large project into manageable parts. Breakdown
  process continues until there are no more steps.

20
Problem-Solving Techniques

• Problem-Solving Steps

21
Problem-Solving Techniques

• Problem-Solving Steps
• Identify the problem.

22
Problem-Solving Techniques

• Problem-Solving Steps
• Identify the problem.
• Analyze the problem.

23
Problem-Solving Techniques

• Problem-Solving Steps
• Identify the problem.
• Analyze the problem.
• Brainstorm solutions and choose the best one.

24
Problem-Solving Techniques

• Problem-Solving Steps
• Identify the problem.
• Analyze the problem.
• Brainstorm solutions and choose the best one.
• Write the algorithm.

25
Problem-Solving Techniques

• Problem-Solving Steps
• Identify the problem.
• Analyze the problem.
• Brainstorm solutions and choose the best one.
• Write the algorithm.
• Prototype the solution.

26
Problem-Solving Techniques

• Problem-Solving Steps
• Identify the problem.
• Analyze the problem.
• Brainstorm solutions and choose the best one.
• Write the algorithm.
• Prototype the solution.
• Implement and test the solution.

27
Problem-Solving Techniques

• Step-by-step pseudocode algorithm for changing a
  lightbulb.

28
The Evolution of Programming Approaches

• Structured Programming

29
The Evolution of Programming Approaches

• Structured Programming
• Creates groups of instructions as independent
  elements.

30
The Evolution of Programming Approaches

• Structured Programming
• Creates groups of instructions as independent
  elements.
• Structured groups of instructions are built on a
  routine, which is a section of a program to
  handle a function.

31
The Evolution of Programming Approaches

• Structured Programming
• Creates groups of instructions as independent
  elements.
• Structured groups of instructions are built on a
  routine, which is a section of a program to
  handle a function.
• A routine is broken down into steps to accomplish
  the function.

32
The Evolution of Programming Approaches

• Modules

33
The Evolution of Programming Approaches

• Modules
• Code modules handle separate components of a
  program.

34
The Evolution of Programming Approaches

• Modules
• Code modules handle separate components of a
  program.
• Each module is a solid portion of a larger
  structure.

35
The Evolution of Programming Approaches

• Modules
• Code modules handle separate components of a
  program.
• Each module is a solid portion of a larger
  structure.
• Modules are reusable, and modularity helps in
  tracking down errors.

36
The Evolution of Programming Approaches

• Modules
• Code modules handle separate components of a
  program.
• Each module is a solid portion of a larger
  structure.
• Modules are reusable, and modularity helps in
  tracking down errors.
• A macro is a recording of steps to perform a
  repetitive task.

37
The Evolution of Programming Approaches

• Object-Oriented Programming

38
The Evolution of Programming Approaches

• Object-Oriented Programming
• Object-oriented programming (OOP) defines each
  module (object) with definite rules for
  interfacing and a protected set of variables.

39
The Evolution of Programming Approaches

• Object-Oriented Programming
• Object-oriented programming (OOP) defines each
  module (object) with definite rules for
  interfacing and a protected set of variables.
• Protected variables allow a programmer to prevent
  data from being altered during program execution.

40
The Evolution of Programming Approaches

• Rapid Application Development

41
The Evolution of Programming Approaches

• Rapid Application Development
• Rapid application development (RAD) reduces cost
  by decreasing time needed to develop a project.

42
The Evolution of Programming Approaches

• Rapid Application Development
• Rapid application development (RAD) reduces cost
  by decreasing time needed to develop a project.
• Programmers using RAD follow guidelines
• Use visual development (4GL) tools when
  possible
• Rapidly prototype new projects
• Approach coding with these priorities
• Use existing code first.
• Buy someone elses code second.
• Write new code last.

43
Programming Development and Documentation Tools

• Compilers and Interpreters

44
Programming Development and Documentation Tools

• Compilers and Interpreters
• Compiler program that translates programming
  language source code into machine code

45
Programming Development and Documentation Tools

• Compilers and Interpreters
• Compiler program that translates programming
  language source code into machine code
• Interpreter translates instructions one-by-one
  as source code is being executed identifies
  errors as they are encountered, including the
  line containing the error

46
Programming Development and Documentation Tools

• Debuggers

47
Programming Development and Documentation Tools

• Debuggers
• Debugger a software tool that helps programmers
  find errors quickly.

48
Programming Development and Documentation Tools

• Debuggers
• Debugger a software tool that helps programmers
  find errors quickly.
• Allows programmers to examine closely what is
  happening when a program runs.

49
Programming Development and Documentation Tools

• Debuggers
• Debugger a software tool that helps programmers
  find errors quickly.
• Allows programmers to examine closely what is
  happening when a program runs.
• Usually an integral component of compilers and
  interpreters.

50
Programming Development and Documentation Tools

• Document Tools

51
Programming Development and Documentation Tools

• Document Tools
• Flowchart provides a visual diagram of an
  algorithm

52
Programming Development and Documentation Tools

• Document Tools
• Flowchart provides a visual diagram of an
  algorithm
• CASE tools help programming team schedule and
  coordinate its operations

53
Programming Development and Documentation Tools

• Document Tools
• Flowchart provides a visual diagram of an
  algorithm
• CASE tools help programming team schedule and
  coordinate its operations
• Comment informal message inserted into a
  program usually to explain source code to later
  users

54
Programming Development and Documentation
Tools

• These symbols are used in flowcharts to represent
  the logic of a program.

55
Programming Development and Documentation
Tools

• Flowcharts help programmers visualize the steps
  in a software program.

56
Programming Development and Documentation Tools

• Flowcharts help programmers visualize the steps
  in a software program.

57
Programming Errors

• What programming errors are in programs?

58
Programming Errors

• What programming errors are in programs?
• Syntax errors typing errors or misunderstanding
  of rules of the language

59
Programming Errors

• What programming errors are in programs?
• Syntax errors typing errors or misunderstanding
  of rules of the language
• Logic errors program instructs computer to
  perform an action incorrectly

60
Programming Errors

• What programming errors are in programs?
• Syntax errors typing errors or misunderstanding
  of rules of the language
• Logic errors program instructs computer to
  perform an action incorrectly
• Run-time errors mistakes that occur when an
  application is running (crash or infinite loop)

61
Programming Errors

• What programming errors are in programs?
• Syntax errors typing errors or misunderstanding
  of rules of the language
• Logic errors program instructs computer to
  perform an action incorrectly
• Run-time errors mistakes that occur when an
  application is running (crash or infinite loop)
• Style errors poorly written programming code
  that may cause dissatisfaction with program

62
The Software Development Life Cycle

• What are the steps in the software development
  life cycle?
• The software development life cycle involves
  planning, designing, implementing, testing, and
  release of application software.

63
Major Programming Languages

• Commonly used programming languages

64
Major Programming Languages

• Machine Code

65
Major Programming Languages

• Machine Code
• programming language that computers actually read
  and interpret

66
Major Programming Languages

• Machine Code
• programming language that computers actually read
  and interpret
• machine code written in a binary string of 1s and
  0s

67
Major Programming Languages

• Machine Code
• programming language that computers actually read
  and interpret
• machine code written in a binary string of 1s and
  0s
• difficult to memorize the long binary strings
  that comprise the machine code

68
Major Programming Languages

• Assembly Language

69
Major Programming Languages

• Assembly Language
• uses symbols and words to represent elements of
  machine code

70
Major Programming Languages

• Assembly Language
• uses symbols and words to represent elements of
  machine code
• must be converted to machine code by a compiler

71
Major Programming Languages

• Assembly Language
• uses symbols and words to represent elements of
  machine code
• must be converted to machine code by a compiler
• runs fastest and uses least memory

72
Major Programming Languages

• Assembly Language
• uses symbols and words to represent elements of
  machine code
• must be converted to machine code by a compiler
• runs fastest and uses least memory
• programs are difficult to write and development
  times are lengthened

73
Major Programming Languages

• COBOL

74
Major Programming Languages

• COBOL
• used chiefly for business applications by large
  institutions and companies

75
Major Programming Languages

• COBOL
• used chiefly for business applications by large
  institutions and companies
• is slow and cumbersome language, but has large
  body of existing code and many programmers know
  the language

76
Major Programming Languages

• RPG

77
Major Programming Languages

• RPG
• commonly used in business environments

78
Major Programming Languages

• RPG
• commonly used in business environments
• inefficient, but simplifies coding of database
  applications

79
Major Programming Languages

• RPG
• commonly used in business environments
• inefficient, but simplifies coding of database
  applications
• is familiar to many programmers

80
Major Programming Languages

• RPG
• commonly used in business environments
• inefficient, but simplifies coding of database
  applications
• is familiar to many programmers
• often used on midrange and mainframe computers

81
Major Programming Languages

• FORTRAN

82
Major Programming Languages

• FORTRAN
• for many years, the language of choice for
  math, science, and engineering projects

83
Major Programming Languages

• FORTRAN
• for many years, the language of choice for
  math, science, and engineering projects
• still in use today in factories and laboratories

84
Major Programming Languages

• BASIC

85
Major Programming Languages

• BASIC
• high-level language that is friendlier and more
  natural than COBOL or FORTRAN

86
Major Programming Languages

• BASIC
• high-level language that is friendlier and more
  natural than COBOL or FORTRAN
• runs slowly, but faster to develop for programmers

87
Major Programming Languages

• BASIC
• high-level language that is friendlier and more
  natural than COBOL or FORTRAN.
• runs slowly, but faster to develop for
  programmers.
• This sequence of code will print the numbers 1 to
  10.

88
Major Programming Languages

• Visual Basic (VB)

89
Major Programming Languages

• Visual Basic (VB)
• language of choice for developing software
  prototypes or for developing interfaces for
  Windows platforms

90
Major Programming Languages

• Visual Basic (VB)
• language of choice for developing software
  prototypes or for developing interfaces for
  Windows platforms
• quick and easy to develop, but run slowly and is
  demanding of RAM and disk space

91
Major Programming Languages

• Visual Basic (VB)
• language of choice for developing software
  prototypes or for developing interfaces for
  Windows platforms
• quick and easy to develop, but run slowly and is
  demanding of RAM and disk space
• supports graphic interfaces

92
Major Programming Languages

• C

93
Major Programming Languages

• C
• compromise between high-level and low-level
  languages, containing components of BASIC and
  assembly language

94
Major Programming Languages

• C
• compromise between high-level and low-level
  languages, containing components of BASIC and
  assembly language
• not as easy to read as BASIC, but runs
  considerably faster and uses less space

95
Major Programming Languages

• C

96
Major Programming Languages

• C
• superset of C any C program should run in C

97
Major Programming Languages

• C
• superset of C any C program should run in C
• added features such as object-oriented programming

98
Major Programming Languages

• C
• superset of C any C program should run in C.
• added features such as object-oriented
  programming.
• This sequence of code will print the numbers 1 to
  10.

99
Major Programming Languages

• C

100
Major Programming Languages

• C
• modern object-oriented language derived from C
  and Java

101
Major Programming Languages

• C
• modern object-oriented language derived from C
  and Java
• combines productivity of Visual Basic with power
  of C

102
Major Programming Languages

• C
• modern object-oriented language derived from C
  and Java
• combines productivity of Visual Basic with power
  of C
• allows use of features in Microsoft.NET
  framework, C, and Microsofts Component Object
  Model (COM)

103
Major Programming Languages

• Scripting Languages

104
Major Programming Languages

• Scripting Languages
• interpreted language that is relatively easy to
  learn and use

105
Major Programming Languages

• Scripting Languages
• interpreted language that is relatively easy to
  learn and use
• explains what a computer should do in
  English-like terms but not precisely how the
  computer should do it

106
Major Programming Languages

• Scripting Languages
• interpreted language that is relatively easy to
  learn and use
• explains what a computer should do in
  English-like terms but not precisely how the
  computer should do it
• Hypertext Markup Language (HTML), JavaScript,
  VBScript, and perl are scripting languages

107
Major Program-ming Languages

• This sequence of code directs a browser to
  display buttons users can click to change the
  background color within the Web browser window.

108
Major Programming Languages

• DHTML

109
Major Programming Languages

• DHTML
• allows Web page designers to alter contents of
  Web page screen dynamically

110
Major Programming Languages

• DHTML
• allows Web page designers to alter contents of
  Web page screen dynamically
• allows viewer actions to change contents of a Web
  page

111
Major Programming Languages

• DHTML
• allows Web page designers to alter contents of
  Web page screen dynamically
• allows viewer actions to change contents of a Web
  page
• displays faster than HTML

112
Major Programming Languages

• DHTML
• allows Web page designers to alter contents of
  Web page screen dynamically
• allows viewer actions to change contents of a Web
  page
• displays faster than HTML
• higher quality appearance and more graphically
  responsive to user actions

113
Major Programming Languages

• XHTML

114
Major Programming Languages

• XHTML
• allows Web pages to separate their content from
  the format supported by a Web page

115
Major Programming Languages

• XHTML
• allows Web pages to separate their content from
  the format supported by a Web page
• screens with different sizes and resolutions can
  display the same Web page content without the Web
  designer having to write specialized versions for
  each

116
Major Programming Languages

• Wireless Markup Language (WML)

117
Major Programming Languages

• Wireless Markup Language (WML)
• created specifically for small systems such as
  cell phones and handheld computers

118
Major Programming Languages

• Wireless Markup Language (WML)
• created specifically for small systems such as
  cell phones and handheld computers
• allows designers to build pages that work for
  small screens with limited display and input
  capabilities

119
On the Horizon

• Based on the information presented in this
  chapter and your own experience, what do you
  think is on the horizon?