Think Different Materi STI pert11

(1)

Bahasa-bahasa Pemrograman

Williams, B.K, Stacy C. Sawyer (2007).

Using Information Technology: A Practical Introduction to Computers & Communications. Seventh Edition,

McGraw-Hill, New York. ISBN-13:

978-0-Sumber:

(2)

2

Learning Outcomes

Pada akhir pertemuan ini, diharapkan mahasiswa

akan mampu :

(3)

Outline Materi

• Programming: A Five-Step Procedure

•

5

Generations of Programming

Languages

(4)

10-4

Programming: A Five-Step

Procedure

•

A program is a list of instructions that the computer must

follow to process data into information

•

The five steps are

1. Clarify/define the problem

a. Clarify the program objectives & users

b. Clarify outputs

c. Clarify inputs

d. Clarify processing tasks

e. Study the feasibility of the program

f.

Document the analysis

(5)

Procedure

• Step 2: Design the program

– Create an algorithm or set of steps to solve the

problem

• Traditional structured programming approach

– Determine program logic using top-down approach & modules – Design details using pseudocode or flow charts

• Alternative object-oriented approach

– Use “Use Case” approach to determine program objects, object inheritance, and actions or functions each object can perform – Identify major program components and organize related

functions and associated data into object classes

– This is the approach used by object-oriented languages such as Java, C#, Lisp, Visual Basic, and C++

– For more information on object-oriented programming, visit

http://oopweb.com/ or

(6)

10-6

Programming: A Five-Step

Procedure

(7)

Procedure

• Panel 10.13

• Pseudocode

START

DO WHILE (SO LONG AS) THERE ARE RECORDS Read a customer billing account record IF today’s date is greater than 30 days from date of last customer payment

Calculate total amount due

Calculate 5% interest on amount due

Add interest to total amount due to calculate Grand total

Print on invoice overdue amount ELSE

Calculate total amount due ENDIF

(8)

10-8

Programming: A Five-Step

Procedure

● PANEL 10.14

Example of a program flowchart and

explanation of

flowchart symbols

This example represents a flowchart for a payroll

(9)

Programming: A Five-Step

Procedure

(10)

10-10

Procedure

• Step 3: Code the program

– Translate the logic requirements into a programming

language

– Programming language is a set of rules that tells the

computer what operations to do

– Each programming language has a syntax, or set of

grammatical rules to follow to write valid expressions

• Syntax rules must be followed or there will be

syntax errors

(11)

Procedure

• Step 4: Test the program

– Desk checking is done by the programmer who

checks for syntax errors and logic errors

– Debugging is the process of detecting, locating, and

removing all errors in a computer program

– Beta testing is the process of testing the program

using real data

• One phase of testing uses correct data

• Once the program works, the next phase of

(12)

10-12

Procedure

• Step 5: Document & Maintain the program

– Documentation is written descriptions of what a program is and

how to fix it

– There are several types of documentation that should be written

• User documentation – for the people who will use your

program

• Operator documentation – for the people who run the large

computers the program runs on – so they know what to do if

the program or computer malfunctions

• Programmer documentation – for the next programmer who

must modify and maintain what you have written

– Maintain the program

• Fix any errors that are noticed once the program is in

production

(13)

Object-Oriented & Visual

Programming

• In Object oriented Programming (OOP) data and

processing instructions are combined into an

object that can be reused

– Object

• Self-contained module consisting of reusable code

– Message

• The instruction received by the object indicating it is time to

perform an action

– Method

(14)

10-14

Object-Oriented & Visual

Programming

• Black Box

– Objects are like a black box in that the

actions and the objects are specified, but

the methods used are internal to the object

– This means the programmer that uses an object does not

need to know

how

the program inside the object does what it

does

– For example, Microsoft Excel is like an object

• Most of us use Excel without understanding what the programmers at Microsoft did to make Excel work

• If we had to know that, it would take a lot longer to learn how to use Excel!

(15)

Object-Oriented & Visual

Programming

• 3 basic concepts of OOP

– Encapsulation

• One object contains (encapsulates) both – Data

– Relevant processing instructions

– Inheritance

• One object can be used as the foundation for other objects • Objects can be arranged in hierarchies – classes and

subclasses

• Objects can inherit actions and attributes from each other

– Polymorphism

• Allows a single definition to be used with different data types and different functions

(16)

10-16

Object-Oriented & Visual

Programming

Doors Have a Handle

open close

Patio doors Have a slider

slide open slide closed Front doors Have locks Car doors Have locks Have windows The “Door” class Actions performed by a door Subclasses of doors inherit from the door class, but also have their own unique actions and attributes

Notice we only list the actions & attributes when

they differ from those of class

(17)

Object-Oriented & Visual

Programming

• Visual Basic is an example of visual

programming

– Using a mouse, the programmer drags and drops

objects on screen

– The objects are arranged to make up the graphical

user interface for the program being written

– By double-clicking on those objects, the programmer

can get into a coding window and write the programs

to control the actions and behaviors of those objects

– This makes it fast and easy to build prototype user

(18)

10-18

Markup & Scripting Languages

• A markup language is a kind of coding or “tags”

inserted into text that embeds details about the

structure and appearance of the text.

• Open up a text editor such as Notepad or

Wordpad, and enter the following text:

• Then save the file on your desktop. Name it sample.htm

• Now open your internet browser and view it by clicking “file open”

and navigating to your desktop

<b><i><font color=“red”>your name</font></i></b></p> And I <b><h1>love</h1></b> this class!!!

(19)

Markup & Scripting Languages

• So how did this

• Turn into this?

• By HTML

your name

And I

love

this class!!!

The <body bgcolor = “”> tag defines the page color The <h2> tag means a heading of size 2

The <h1> tag means a heading of size 1 The <i> tag means to italicize the text

The <b> tag means to bold the text

(20)

10-20

Markup & Scripting Languages

• HTML

– Hypertext markup language

– Used to create web pages

– Also lets you insert a hypertext link in a web page

• VRML

– Virtual Reality Modeling for Markup Language is used

to create three-dimensional web pages including

interactive animation

(21)

Markup & Scripting Languages

• XML

– eXtensible Markup Language is a metalanguage

written in SGML that allows one to facilitate easy

document interchange on the internet

– XML lets you create your own tags

– XML statements define data content

• JavaScript

– Not the same language as Java

(22)

10-22

Markup & Scripting Languages

• ActiveX

– Developed by Microsoft as an alternative to

Java for creating interactivity on web pages

– A set of controls or components that enable

programs or content of almost any type to be

embedded in a web page

– Often used by crackers to propagate viruses

and/or trojans

– Before you allow an ActiveX component to

(23)

Markup & Scripting Languages

• Perl

– A general-purpose programming language

developed for text manipulation.

– Developed in 1987 by Larry Wall

– Now used for web development, network

programming, system administration, GUI

development, other tasks