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(1) JavaScript. (2) JavaScript vs. Java JavaScript and Java are completely different Java, invented by Sun in 1995, is a complex programming language.

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Presentation on theme: "(1) JavaScript. (2) JavaScript vs. Java JavaScript and Java are completely different Java, invented by Sun in 1995, is a complex programming language."— Presentation transcript:

1 (1) JavaScript

2 (2) JavaScript vs. Java JavaScript and Java are completely different Java, invented by Sun in 1995, is a complex programming language and platform JavaScript, invented by Brendan Eich in 1995, is a scripting language. - First used by the Netscape browser - Adopted by ECMA in 1997 - Provides access the the HTML Document Object Model (DOM)

3 (3) Document Object Model Platform and language neutral interface Allows programs and scripts to dynamically access and update: Content Structure Style of HTML documents

4 (4) DOM Represents the document as a forest of Nodes foo bar baz qux foobarbazqux

5 (5) DOM Interfaces DOMException only raised in ‘exceptional’ cases Document : Node DocumentType, DOMImplementation, Element Element createElement(tag) raises DOMException Text createTextNode(data) Comment createComment(data) Attr createAttribute(name) raises DOMException Element getElementById(id) NodeList getElementsByTagName(name) NodeList getElementsByClassName(name)

6 (6) DOM Interface Node NodeType, parentNode, childNodes Node insertBefore(newChild, refChild) raises DOMException Node replaceChild(newChild, oldChild) raises DOMException Node removeChild(oldChild) raises DOMException Node appendChild(newChild) raises DOMException boolean hasChildNodes()

7 (7) DOM Interface Element DOMString getAttribute(name) setAttribute(name, value) Attr getAttributeNode(name) Attr setAttributeNode(newAttr) NodeList getElementsByTagName(name)

8 (8) JavaScript Placed inside tags no longer need type=“text/javascript” tags can be in or loads external script file

9 (9) JavaScript Structure Statements tell the browser what to do var x=3; Should end with ; Code is a sequence of JavaScript statements Blocks of code is grouped with {} JavaScript is case sensitive myVar != myvar Uses C++ comments // and /* */

10 (10) JavaScript Types Strings var fname=‘Cam’; var lname=“Moore”; Numbers var x=3; var y=2.1; Boolean true, false Arrays var foo=Array(); var bar=[‘a’, ‘b’, 3]; Objects var person={fname:”John”, lname:”Doe”, id=3}

11 (11) JavaScript Functions Functions use the ‘function’ keyword function myFunction(name, job) { alert(“Welcome “ + name + “, the “ + job); var x=5; return x; }

12 (12) JavaScript Operators Arithmetic: +, -, *, /, %, ++, -- Assignment: =, +=, -=, *=, /=, %= Comparison: ==, ===, !=, >, =, <= Logical: &&, ||, ! Condition: x=(condition)?value1:value2;

13 (13) Condition Statements if(condition){…} if(condition){…}else{…} if(condition){…}else if(condition2){…}else{…} switch(n){case 1:…break;…;default:…}

14 (14) Loops for(init; condition; increment) {…} - Classic for loop for(x in person) {…} - Loops over all properties in person while(condition){…} - Classic while loop do{…}while(condition); - Classic do/while loop

15 (15) JavaScript Labels Similar to goto statements (EVIL) label: … break label; … continue label;


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