LBSC 690 Session 5A Programming
Languages How do we learn a language? Learn by listening Then reading Then writing How do we teach programming? Learn to write first Contributes to programming problems
Programming Languages Programs are written in a programming language. Two types: Procedural and non-procedural (declarative). Are artificial languages.
Artificial Languages Consist of: A set of symbols (an alphabet) A vocabulary Controlled segment (an authority list) A user-defined segment Syntax Semantics
Levels of Languages “Low” to “high” Machine language Lowest level All languages must be translated into this to run on the computer Unique to each platform Next level: Assembler
Levels (Cont’d) Higher Level Languages: Basic, Pascal, C, Fortran, Cobol, Visual Basic, Visual C, etc. Fourth Generation Languages: NOMAD, QBE, etc. Object Oriented Languages: Smalltalk, C++, Java.
Software Tools Facilitate writing programs: Compilers & Interpreters. Software Development Environments.
What is HTML? HyperText Markup Language. Based on Standard Generalized Markup Language (STML). Describes the structure of a document. Not its presentation. Does not describe page layout. Designed to be used cross-platform.
HTML is a Markup Language Start with text and add special tags around words and paragraphs. Tags indicate different parts of a page and produce different effects in the browser. HTML has a given, defined set of tags. Users cannot create their own.
HTML Versions HTML 2.0. Base set of tags. HTML 3.2. Second release. HTML 4.0. Current generation. Includes new features for flexibility. HTML Has corrections for 4.0.
What do HTML Files look like? Contain: Text of page itself, HTML tags indicating page elements, structure, formatting and hypertext links to other pages or to included media. Look at HTML sources. For example, with Netscape use:
Creating Page Use a text editor. Saves files in ASCII format. In Unix, pico is a text editor, In Windows, Notepad and DOS Edit are text editors. View your created page with a browser.
Tags All text and HTML commands require beginning and ending HTML tags: … your page… {The forward slash indicates the end.}. This tag indicates that the content of this file is in HTML.
Tags (Cont’d.) tag: Specifies that the lines in it are prologue, e.g., the title:. tag: Encloses the remainder of the text and other contents (links, pictures, etc). tags are Headings that divide sections of text.(Can be up to 6 levels).
Tags (Cont’d). tags indicate paragraphs. HTML defines five kinds of lists: Numbered lists:. Bulleted or,unordered, lists:. Glossary lists:. Menu lists:. Comments:.
Sources of Help for HTML Specifications: A Beginner’s Guide to HTML: HTMLPrimer.htmlwww.ncsa.uiuc.edu/General/Internet/WWW/ HTMLPrimer.html. Laura Lemay,Teach yourself Web Publishing with HTML 4 in a Week, Fourth Edition,SamsNet Ed Tittel, HTML for Dummies, IDG Books, 1997.
Tags (Cont’d.)