im 215 intro to scripting languages
DESCRIPTION
IM 215 Intro to Scripting Languages. Objectives. The core objectives of this course are as follows: Students will understand basic foundations of JavaScript, including its usage in the web and application design and development. - PowerPoint PPT PresentationTRANSCRIPT
IM 215Intro to Scripting
Languages
Objectives
The core objectives of this course are as follows:
• Students will understand basic foundations of JavaScript, including its usage in the web and application design and development.
• Students will understand basic foundations of Flash/ActionScript, including its usage in the web and application design and development.
• Students will understand the foundations of mobile applications development.
Academic policies
• Lab use
• Communication about grades
• Academic honesty
• Exam and quiz policy
• Late work
Assessment criteria
• Assessments:Class participation - 4 Quizzes – 25 points eachJavascript Assignment 1 – 40 pointsJavascript Assignment 2 – 40 pointsJavascript Assignment 3 – 50 pointsActionscript Assignment 1 – 20 pointsActionscript Assignment 2 – 25 pointsActionscript Assignment 3 – 35 pointsActionscript Assignment 4 – 50 pointsFinal Exam – 100 points
Grades/Resources
• >= 90% A Excellent
• >=80% and < 90% B Above Average
• >=70% and < 80% C Average
• >=60% and <70% D Below Average
• < 60% F Fails
• Javascript, A Beginner’s Guide, 3rd Edition by John Pollock
• Foundation Actionscript 3.0 by Yard, Webster and McSharry
Contact details
• Email: [email protected]
• AIM: marktee07
• Twitter: em_tee
• After lectures on Monday’s and Wednesday’s
JavascriptIntroduction
Javascript• Adds interactivity and effects to a static
HTML page
• Limited to client side actions
• Wikipedia.com – no javascript interactions
• Amazon.com – significant javascript enhancements
First steps..• Tools of the trade• A text editor
TextWrangler (http://www.barebones.com/products/TextWrangler/)Notepad++
(http://notepad-plus.sourceforge.net/uk/site.htm) • A browser
Firefox (current version 3.5.7)Internet Explorer (version 7)
• Edit code in your text editor
• When ready to try your code, open in the browser
Simple HTML page<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN“
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>Simple static page</title>
</head>
<body>
<p>IM215 rocks</p>
</body>
</html>
First script
Add the following to our page:
<script type=“text/javascript”>document.write(‘<p>And so does Javascript</p>’);
</script>
Save the page and re-open it in your browser.
External script
Create a new file and insert the following line:
document.write(‘<p>Written in from outside</p>’);
Save it as external.js
Return to our original html file and insert the following:
<script type=“text/javascript” src=“external.js”></script>
Variables
• Variables are containers for data
• datum – individual piece of data
• name - label that identifies the piece of datum
• variable – consists of a name and a piece of data
• A variable’s datum is called its “value”
Variables (cont.)
1. Simplify code and save time, giving commonly referenced values a single name
2. Acts as a placeholder for unknown values, e.g. user input
3. Clarifies code, allowing you to give meaningful names to values used in code
Using Variables
• Defining:var variableName;
• Giving, or “Assigning”, a value:variableName=25;
Or, combined:var variableName=25;
Variable rules
• Variable names are case sensitive.
• Can only contain letters, numbers or underscores.
• Cannot begin with a number.
• Cannot be one of a set of Javascript reserved words.
• Use meaningful names.
Variable Data Types
• The current value of a variable has a “type”
• Javascript has 3 core data types• Number – Any number including decimal
numberse.g. var numVar=25;
• String – any sequence of characterse.g. var stringVar=“A string of text”;
• Boolean – true or false
Using Variables
• To reference a variable, include the name in the context of other code.
• For example,var ourString=“An assigned string”;document.write(ourString);
Comments
• Lines in code that get ignored by the JavaScript engine.
• Provide clarity, allowing you to explain the overall purpose of your code in plain english.
• Valuable when collaborating on code with others, and for your own future reference.
Comments
• Single line:// This line is a comment
• Multi-line:/*This is a multi-line commentEverything within here is ignored*/
Sources:
• “JavaScript: A Beginner’s Guide” by John Pollock