Bahasa-bahasa Pemrograman (Lanjutan) Pertemuan 26
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Matakuliah Tahun Versi : T0604-Pengantar Teknologi Informasi : 2008 : 2.0/0.0 Pertemuan 26 Bahasa-bahasa Pemrograman (Lanjutan) Sumber: Chapter 10. System Analysis & Programming: S/W Development, Programming, & Languages, p.497 Williams, B.K, Stacy C. Sawyer (2007). Using Information Technology: A Practical Introduction to Computers & Communications. Seventh Edition, McGraw-Hill, New York. ISBN-13: 978-007-110768-6 1 Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : • menjelaskan cara kerja pemrograman berorientasi obyek dan pemrograman visual, serta apa yg dikerjakan bahasa markup dan bahasa scripting (C2) 2 Outline Materi • Object-Oriented & Visual Programming • Markup & Scripting Languages 3 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 • The processing instructions within the object to perform the specified action 10-4 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! • Programmers who use objects can write programs a lot faster, because objects save so much work 10-5 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 • Means a message produces different results depending on the object it is sent to 10-6 Object-Oriented & Visual Programming Example of Inheritance Hierarchy with Specialization Actions performed by a door Patio doors Have a slider slide open slide closed Notice we only list the actions & attributes when they differ from those of class Doors Have a Handle open close Front doors Have locks 10-7 The “Door” class Subclasses of doors inherit from the door class, but also have their own unique actions and attributes Car doors Have locks Have windows 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 interfaces and get end-user approval before doing a lot of programming If you have Visual Basic installed on your school’s computers, this would be a great time to try it out. 10-8 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: <body bgcolor = "yellow"> <h2> <p>My name is </h2> <b><i><font color=“red”>your name</font></i></b></p> And I <b><h1>love</h1></b> this class!!! </body> • 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 10-9 Markup & Scripting Languages • So how did this • Turn into this? My name is your name And I love this class!!! <body bgcolor = "yellow"> <h2> <p>My name is </h2> <b><i><font color=“red”>your name</font></i></b></p> And I <b><h1>love</h1></b> this class!!! </body> 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 The <p> tag means to start a new paragraph • By HTML tags And the / inside a tag means to end that format There are a LOT of other HTML tags 10-10 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 – Requires special VRML browser to view those pages 10-11 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 – An object-oriented scripting language that adds interactive functions to web pages 10-12 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 download from your browser to your PC, make sure you trust that website! 10-13 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 – Widely used for web server programs to perform automatic tasks such as updating user accounts and newsgroup postings 10-14 Kesimpulan 15
