- JavaScript
Infobox programming language
name = JavaScript
paradigm =Multi-paradigm : prototype-based, functional, imperative, scripting
year = 1995
designer =Brendan Eich
developer =Netscape Communications Corporation ,Mozilla Foundation
latest_release_version = 1.8
latest_release_date = 2008
typing = dynamic, weak, duck
implementations = SpiderMonkey, Rhino, KJS, JavaScriptCore
dialects =JScript ,JScript .NET
influenced_by = Self, C, Scheme,Perl , Python, Java
operating_system =
license =
website =JavaScript is a
scripting language most often used forclient-side web development. It was the originating dialect of theECMAScript standard. It is a dynamic, weakly typed, prototype-based language withfirst-class function s. JavaScript was influenced by many languages and was designed to look like Java, but be easier for non-programmers to work with. [ [http://wp.netscape.com/columns/techvision/innovators_be.html TechVision: Innovators of the Net: Brendan Eich and JavaScript] ] [ [http://weblogs.mozillazine.org/roadmap/archives/2008/04/popularity.html Brendan's Roadmap Updates: Popularity] ]Although best known for its use in
website s (asclient-side JavaScript ), JavaScript is also used to enable scripting access to objects embedded in other applications (see below).JavaScript, despite the name, is essentially unrelated to the Java programming language, although both have the common C syntax, and JavaScript copies many Java names and naming conventions. The language was originally named "LiveScript" but was renamed in a co-marketing deal between
Netscape and Sun, in exchange for Netscape bundling Sun's Java runtime with their then-dominant browser. The key design principles within JavaScript are inherited from the Self and Scheme programming languages. [cite web|title=ECMAScript Language Overview|url=http://www.ecmascript.org/es4/spec/overview.pdf|pages=p.4|date=2007-10-23]"JavaScript" is a
trademark of Sun Microsystems. It was used under license for technology invented and implemented by Netscape Communications and current entities such as theMozilla Foundation . [cite web|title=Sun Trademarks|url=http://www.sun.com/suntrademarks/|publisher=Sun Microsystems|accessdate=2007-11-08]History and naming
JavaScript was originally developed by
Brendan Eich of Netscape under the name "Mocha", which was later renamed to "LiveScript", and finally to JavaScript. The change of name from LiveScript to JavaScript roughly coincided with Netscape adding support for Java technology in itsNetscape Navigator web browser . JavaScript was first introduced and deployed in the Netscape browser version 2.0B3 in December 1995. The naming has caused confusion, giving the impression that the language is a spin-off of Java, and it has been characterized by many as a marketing ploy by Netscape to give JavaScript the cachet of what was then the hot new web-programming language. [ [http://www.webdevelopersnotes.com/basics/languages_on_the_internet.php3 Programming languages used on the Internet and the World Wide Web (WWW)] ] [ [http://safari.oreilly.com/0596101996/jscript5-CHP-1 O'Reilly - Safari Books Online - 0596101996 - JavaScript: The Definitive Guide, 5th Edition] ]Microsoft named its dialect of the languageJScript to avoid trademark issues. JScript was first supported inInternet Explorer version 3.0, released in August 1996, and it included Y2K-compliant date functions, unlike those based on [http://java.sun.com/j2se/1.4.2/docs/api/java/util/Date.html java.util.Date] in JavaScript at the time. The dialects are perceived to be so similar that the terms "JavaScript" and "JScript" are often used interchangeably (including in this article). Microsoft, however, notes dozens of ways in which JScript is [http://msdn2.microsoft.com/en-us/library/4tc5a343.aspx not ECMA compliant] .Netscape submitted JavaScript to
Ecma International for standardization resulting in the standardized version namedECMAScript . [ [http://cgi.netscape.com/newsref/pr/newsrelease289.html Netscape Press Release] ]Features
tructured programming
JavaScript supports all the
structured programming syntax in C (e.g.,if
statements,while
loops,switch
statements, etc.). One partial exception is scoping: C-style block-level scoping is not supported. JavaScript 1.7, however, supports block-level scoping with thelet
keyword. Like C, JavaScript makes a distinction between expressions and statements.Dynamic programming
; dynamic typing: As in most scripting languages, types are associated with values, not
variables . For example, a variablex
could be bound to a number, then later rebound to a string. JavaScript supports various ways to test the type of an object, includingduck typing . [cite book
last = Flanagan
first = David
authorlink = David Flanagan
title = JavaScript: The Definitive Guide
publisher =O'Reilly Media
year = 2006
pages = pp. 176-178
isbn = 0596101996 ] ; objects as associative arrays: JavaScript is heavilyobject-based . Objects areassociative array s, augmented with prototypes (see below). Object property names are associative array keys:obj.x = 10
andobj ["x"] = 10
are equivalent, the dot notation being merelysyntactic sugar . Properties and their values can be added, changed, or deleted at run-time. The properties of an object can also be enumerated via afor...in
loop.; run-time evaluation: JavaScript includes aneval function that can execute statements provided as strings at run-time.Functional programming
; first-class functions: Functions are first-class; they are objects themselves. As such, they have properties and can be passed around and interacted with like any other object.; inner functions and closures: Inner functions (functions defined within other functions) are created each time the outer function is invoked, and variables of the outer functions for that invocation continue to exist as long as the inner functions still exist, even after that invocation is finished (e.g. if the inner function was returned, it still has access to the outer function's variables) — this is the mechanism behind closures within JavaScript.
Prototype-based
; prototypes: JavaScript uses prototypes instead of classes for defining object properties, including methods, and inheritance. It is possible to simulate many class-based features with prototypes in JavaScript.; functions as object constructors: Functions double as object constructors along with their typical role. Prefixing a function call with
new
creates a new object and calls that function with its localthis
keyword bound to that object for that invocation. The function'sprototype
property determines the new object's prototype.; functions as methods : Unlike many object-oriented languages, there is no distinction between a function definition and a method definition. Rather, the distinction occurs during function calling; a function can be called as a method. When a function is invoked as a method of an object, the function's localthis
keyword is bound to that object for that invocation.Others
; run-time environment: JavaScript typically relies on a run-time environment (e.g. in a web browser) to provide objects and methods by which scripts can interact with "the outside world". (This is not a language feature per se, but it is common in most JavaScript implementations.); variadic functions : An indefinite number of parameters can be passed to a function. The function can both access them through
formal parameter s and the localarguments
object.; array and object literals: Like many scripting languages, arrays and objects (associative arrays in other languages) can be created with a succinct shortcut syntax. The object literal in particular is the basis of theJSON data format.; regular expressions: JavaScript also supportsregular expression s in a manner similar toPerl , which provide a concise and powerful syntax for text manipulation that is more sophisticated than the built-in string functions.yntax
As of 2008, the latest version of the language is JavaScript 1.8. It is a superset of
ECMAScript (ECMA-262) Edition 3. Extensions to the language, including partialE4X (ECMA-357) support and experimental features considered for inclusion into ECMAScript Edition 4, are documented [http://developer.mozilla.org/en/docs/Core_JavaScript_1.5_Reference:About here] .Sample code:
Use in web pages
The primary use of JavaScript is to write functions that are embedded in or included from
HTML pages and interact with theDocument Object Model (DOM) of the page. Some simple examples of this usage are:* Opening or popping up a new window with programmatic control over the size, position, and attributes of the new window (i.e. whether the menus, toolbars, etc. are visible).
*Validation of web form input values to make sure that they will be accepted before they are submitted to the server.
* Changing images as the mouse cursor moves over them: This effect is often used to draw the user's attention to important links displayed as graphical elements.Because JavaScript code can run locally in a user's browser (rather than on a remote server) it can respond to user actions quickly, making an application feel more responsive. Furthermore, JavaScript code can detect user actions which HTML alone cannot, such as individual keystrokes. Applications such as
Gmail take advantage of this: much of the user-interface logic is written in JavaScript, and JavaScript dispatches requests for information (such as the content of an e-mail message) to the server. The wider trend of Ajax programming similarly exploits this strength.A "JavaScript engine" (also known as "JavaScript interpreter" or "JavaScript implementation") is an interpreter that interprets JavaScript
source code and executes the script accordingly. The first ever JavaScript engine was created byBrendan Eich atNetscape Communications Corporation , for theNetscape Navigator web browser . The engine, code-namedSpiderMonkey , is implemented in C. It has since been updated (in JavaScript 1.5) to conform to ECMA-262 Edition 3. The Rhino engine, created primarily by Norris Boyd (also at Netscape) is a JavaScript implementation in Java. Rhino, like SpiderMonkey, is ECMA-262 Edition 3 compliant.The most common host environment for JavaScript is by far a web browser. Web browsers typically use the public API to create "host objects" responsible for reflecting the DOM into JavaScript. The
web server is another common application of the engine. A JavaScript webserver would expose host objects representing anHTTP request and response objects, which a JavaScript program could then manipulate to dynamically generate web pages.A minimal example of a web page containing JavaScript (using HTML 4.01 syntax) would be:
Compatibility considerations
The DOM interfaces for manipulating web pages are not part of the ECMAScript standard, or of JavaScript itself. Officially, they are defined by a separate standardization effort by the W3C; in practice, browser implementations differ from the standards and from each other, and not all browsers execute JavaScript.
To deal with these differences, JavaScript authors can attempt to write standards-compliant code which will also be executed correctly by most browsers; failing that, they can write code that checks for the presence of certain browser features and behaves differently if they are not available. [Peter-Paul Koch, [http://www.quirksmode.org/js/support.html Object detection] ] In some cases, two browsers may both implement a feature but with different behavior, and authors may find it practical to detect what browser is running and change their script's behavior to match. [Peter-Paul Koch, [http://www.evolt.org/node/23335 Mission Impossible - mouse position] ] [Peter-Paul Koch, [http://www.quirksmode.org/js/detect.html Browser detect] ] Programmers may also use libraries or toolkits which take browser differences into account.
Furthermore, scripts will not work for all users. For example, a user may:
* use an old or rare browser with incomplete or unusual DOM support,
* use a PDA ormobile phone browser which cannot execute JavaScript,
* have JavaScript execution disabled as a security precaution,
* or be visually or otherwise disabled and use a speech browserTo support these users, web authors can try to create pages which degrade gracefully on user agents (browsers) which do not support the page's JavaScript.
ecurity
JavaScript and the DOM provide the potential for malicious authors to deliver scripts to run on a client computer via the web. Browser authors contain this risk using two restrictions. First, scripts run in a sandbox in which they can only perform web-related actions, not general-purpose programming tasks like creating files. Second, scripts are constrained by the
same origin policy : scripts from one web site do not have access to information such as usernames, passwords, or cookies sent to another site. Most JavaScript-related security bugs are breaches of either thesame origin policy or the sandbox.Cross-site vulnerabilities
A common JavaScript-related security problem is
cross-site scripting , or XSS, a violation of the same-origin policy. XSS vulnerabilities occur when an attacker is able to cause a trusted web site, such as an online banking website, to include a malicious script in the webpage presented to a victim. The script in this example can then access the banking application with the privileges of the victim, potentially disclosing secret information or transferring money without the victim's authorization.XSS vulnerabilities can also occur because of implementation mistakes by browser authors. [MozillaZine, [http://www.mozillazine.org/talkback.html?article=4392 Mozilla Cross-Site Scripting Vulnerability Reported and Fixed] ]
XSS is related to
cross-site request forgery or XSRF. In XSRF one website causes a victim's browser to generate fraudulent requests to another site with the victim's legitimateHTTP cookies attached to the request.Misunderstanding the client-server boundary
Client-server applications, whether they involve JavaScript or not, must assume that untrusted clients may be under the control of attackers. Thus any secret embedded in JavaScript could be extracted by a determined adversary, and the output of JavaScript operations should not be trusted by the server. Some implications:
* Web site authors cannot perfectly conceal how their JavaScript operates, because the code is sent to the client, and
obfuscated code can be reverse engineered.
* JavaScript form validation only provides convenience for users, not security. If a site verifies that the user agreed to its terms of service, or filters invalid characters out of fields that should only contain numbers, it must do so on the server, not only the client.
* It would be extremely bad practice to embed a password in JavaScript (where it can be extracted by an attacker), then have JavaScript verify a user's password and pass "password_ok=1" back to the server (since the "password_ok=1" response is easy to forge). [For an example of this bad practice, see http://javascript.internet.com/passwords/]It also does not make sense to rely on JavaScript to prevent user interface operations (such as "view source" or "save image"). This is because a client could simply ignore such scripting. [cite journal
title = Right-click “protection”? Forget about it
journal = blog.anta.net
date =2008-06-17
url = http://blog.anta.net/2008/06/17/right-click-%e2%80%9cprotection%e2%80%9d-forget-about-it/
issn = 1797-1993
accessdate = 2008-06-17 ]Browser and plugin coding errors
JavaScript provides an interface to a wide range of browser capabilities, some of which may have flaws such as
buffer overflow s. These flaws can allow attackers to write scripts which would run any code they wish on the user's system.These flaws have affected major browsers including Firefox [Mozilla Corporation, [http://www.mozilla.org/security/announce/2006/mfsa2006-38.html Buffer overflow in crypto.signText()] ] , Internet Explorer [Paul Festa, CNet, [http://news.com.com/2100-1001-214620.html Buffer-overflow bug in IE] ] , and Safari. [SecurityTracker.com, [http://securitytracker.com/alerts/2006/Mar/1015713.html Apple Safari JavaScript Buffer Overflow Lets Remote Users Execute Arbitrary Code and HTTP Redirect Bug Lets Remote Users Access Files] ]
Plugins, such as video players,
Macromedia Flash , and the wide range ofActiveX controls enabled by default in Microsoft Internet Explorer, may also have flaws exploitable via JavaScript,and such flaws have been exploited in the past. [SecurityFocus, [http://www.securityfocus.com/bid/19030/info Microsoft WebViewFolderIcon ActiveX Control Buffer Overflow Vulnerability] ] [Fusion Authority, [http://www.fusionauthority.com/security/3234-macromedia-flash-activex-buffer-overflow.htm Macromedia Flash ActiveX Buffer Overflow] ] In Windows Vista, Microsoft has attempted to contain the risks of bugs such as buffer overflows by running the Internet Explorer process with limited privileges. [Mike Friedman, [http://blogs.msdn.com/ie/archive/2006/02/09/528963.aspx Protected Mode in Vista IE7] ]andbox implementation errors
Web browsers are capable of running JavaScript outside of the sandbox, with the privileges necessary to, for example, create or delete files. Of course, such privileges aren't meant to be granted to code from the web.
Incorrectly granting privileges to JavaScript from the web has played a role in vulnerabilities in both Internet Explorer [US CERT, [https://www.kb.cert.org/vuls/id/713878 Vulnerability Note VU#713878: Microsoft Internet Explorer does not properly validate source of redirected frame] ] and Firefox [Mozilla Foundation, [http://www.mozilla.org/security/announce/2005/mfsa2005-41.html Mozilla Foundation Security Advisory 2005-41: Privilege escalation via DOM property overrides] ] . In Windows XP Service Pack 2, Microsoft demoted JScript's privileges in Internet Explorer. [Microsoft Corporation, [http://technet.microsoft.com/en-us/library/bb457150.aspx#EHAA Changes to Functionality in Microsoft Windows XP Service Pack 2: Part 5: Enhanced Browsing Security] ]
Some versions of
Microsoft Windows allow JavaScript stored on a computer's hard drive to run as a general-purpose, non-sandboxed program. This makes JavaScript (likeVBScript ) a theoretically viable vector for a Trojan horse, although JavaScript Trojan horses are uncommon in practice. [For one example of a rare JavaScript Trojan Horse, see Symantec Corporation, [http://www.symantec.com/security_response/writeup.jsp?docid=2003-100111-0931-99 JS.Seeker.K] ] (SeeWindows Script Host .)Uses outside web pages
Outside the web, JavaScript interpreters are embedded in a number of tools. Each of these applications provides its own
object model which provides access to the host environment, with the core JavaScript language remaining mostly the same in each application.*
ActionScript , the programming language used inAdobe Flash , is another implementation of the ECMAScript standard.
* Apple's Dashboard Widgets, Microsoft's Gadgets,Yahoo! Widgets , Google Desktop Gadgets are implemented using JavaScript.
* TheMozilla platform, which underlies Firefox and some other web browsers, uses JavaScript to implement thegraphical user interface (GUI) of its various products.
* Adobe's Acrobat and Adobe Reader (formerly Acrobat Reader) support JavaScript in PDF files.
* Tools in theAdobe Creative Suite , including Photoshop, Illustrator,Dreamweaver andInDesign , allow scripting through JavaScript.
* Microsoft'sActive Scripting technology supports the JavaScript-compatibleJScript as an operating system scripting language.
* TheJava programming language , in version SE 6 (JDK 1.6), introduced thejavax.script
package, including a JavaScript implementation based on Mozilla Rhino. Thus, Java applications can host scripts that access the application's variables and objects, much like web browsers host scripts that access the browser's Document Object Model (DOM) for a webpage. [http://java.sun.com/javase/6/webnotes/index.html#scripting javax.script release notes] [Flanagan 5th Edition, Pp 214 et seq]
* Applications on the social network platformOpenSocial are implemented in JavaScript.
* Newer versions of the Qt C++ toolkit include aQtScript
module to interpret JavaScript, analogous tojavax.script
. [Trolltech ASA, [http://doc.trolltech.com/4.3/qtscript.html QtScript Module] ]
* The interactive music signal processing softwareMax/MSP released by Cycling '74, offers a JavaScript model of its environment for use by developers. It allows much more precise control than the default GUI-centric programming model.
* Late Night Software'sJavaScript OSA (aka JavaScript for OSA, or JSOSA), is a freeware alternative toAppleScript for Mac OS X. It is based on the Mozilla 1.5 JavaScript implementation, with the addition of aMacOS
object for interaction with the operating system and third-party applications. [AppleScript#Open_Scripting_Architecture ]
* ECMAScript was included in the VRML97 standard for scripting nodes of VRML scene description files.
* Some high-end Philipsuniversal remote panels, including TSU9600 and TSU9400, can be scripted using JavaScript. [Koninklijke Philips Electronics NV, [http://www.pronto.philips.com/prontoscript/index.cfm?id=1422] ]
* Sphere [ [http://www.spheredev.org/wiki/Main_Page Sphere] ] is an open source and cross platform computer program designed primarily to make role-playing games that uses JavaScript as scripting language.
*Adobe Integrated Runtime is a JavaScript runtime that allows developers to create desktop applications.
* GeoJavaScript enables access to the geospatial extensions in PDF files using TerraGo TechnologiesGeoPDF Toolbar and Adobe Acrobat and Reader.Debugging
Within JavaScript, access to a
debugger becomes invaluable when developing large, non-trivial programs. Because there can be implementation differences between the various browsers (particularly within theDocument Object Model ) it is useful to have access to a debugger for each of the browsers a web application is being targeted at.Currently,
Internet Explorer ,Firefox , Safari, and Opera all have third-party script debuggers available for them.Internet Explorer has three debuggers available for it:
Microsoft Visual Studio is the richest of the three, closely followed by Microsoft Script Editor (a component ofMicrosoft Office [ [http://msdn2.microsoft.com/en-us/library/aa202668(office.11).aspx JScript development in Microsoft Office 11] (MS InfoPath 2003)] ), and finally the freeMicrosoft Script Debugger which is far more basic than the other two. The free [http://www.microsoft.com/express/vwd/ Microsoft Visual Web Developer Express] provides a limited version of the JavaScript debugging functionality in Microsoft Visual Studio.Web applications within Firefox can be debugged using the Firebug plug-in, or the older
Venkman debugger, which also works with theMozilla browser. Firefox also has a simpler built-in Error Console, which logs JavaScript andCSS errors and warnings.Drosera is a debugger for the
WebKit engine [ [http://webkit.org/blog/61/introducing-drosera/ Introducing Drosera - Surfin' Safari] ] on Macintosh and Windows [ [https://bugs.webkit.org/show_bug.cgi?id=16314 Bug tracker discussion on Drosera Windows support] ] powering Apple's Safari.There are also some free tools such as JSLint, a code quality tool that will scan JavaScript code looking for problems [ [http://www.jslint.com/lint.html JSLint help page] ] , as well as a non-free tool called "SplineTech JavaScript HTML Debugger". [ [http://www.javascript-debugger.com/ SplineTech JavaScript HTML Debugger] ]
Since JavaScript is interpreted, loosely-typed, and may be hosted in varying environments, each with their own compatibility differences, a programmer has to take extra care to make sure the code executes as expected in as wide a range of circumstances as possible, and that functionality degrades gracefully when it does not.
Versions
The next major version of JavaScript, 2.0, will conform to ECMA-262 4th edition. [ [http://ejohn.org/blog/versions-of-javascript Versions of JavaScript] ]
Related languages
There is not a particularly close genealogical relationship between Java and JavaScript; their similarities are mostly in basic syntax because both are ultimately derived from C. Their semantics are quite different and their object models are unrelated and largely incompatible. In Java, as in C and C++, all data is statically typed, whereas JavaScript variables, properties, and array elements may hold values of any type.
The standardization effort for JavaScript also needed to avoid trademark issues, so the ECMA 262 standard calls the language
ECMAScript , three editions of which have been published since the work started in November 1996.Microsoft's
VBScript , like JavaScript, can be run client-side in web pages. VBScript has syntax derived fromVisual Basic and is only supported by Microsoft'sInternet Explorer .JSON , or JavaScript Object Notation, is a general-purpose data interchange format that is defined as a subset of JavaScript.JavaScript is also considered a
functional programming language like Scheme andOCaml because it has closures and supportshigher-order function s. [ [http://www.crockford.com/javascript/little.html The Little JavaScripter] shows the relationship with Scheme in more detail.]Mozilla browsers currently support
LiveConnect , a feature that allows JavaScript and Java to intercommunicate on the web. However, support for LiveConnect is scheduled to be phased out in the future.ee also
*ECMAScript
*JavaScript syntax
*Client-side JavaScript
** AJAX
**Dynamic HTML
*Server-side JavaScript
*JSDoc
*JSON
*JSAN
*Comparison of layout engines (ECMAScript)
*Comparison of Javascript-based source code editors References
Bibliography
*cite book |last=McDuffie |first=Tina Spain |title=JavaScript Concepts & Techniques: Programming Interactive Web Sites |year=2003 |publisher=Franklin, Beedle & Associates |isbn=1-887-90269-4
*cite book |last=McFarlane |first=Nigel |title=Rapid Application Development with Mozilla |year=2003 |publisher=Prentice Hall Professional Technical References |isbn=0-13-142343-6
*cite book |last=Flanagan |first=David |coauthors=Ferguson, Paula |title=JavaScript: The Definitive Guide |edition=4th Edition |year=2002 |publisher=O'Reilly & Associates |location= |isbn=0-596-00048-0
*cite book |last=Flanagan |first=David |title=JavaScript: The Definitive Guide |edition=5th Edition |year=2006 |publisher=O'Reilly & Associates |isbn=0-596-10199-6
*cite book |last=Goodman |first=Danny |coauthors=Markel, Scott |title=JavaScript and DHTML Cookbook |year=2003 |publisher=O'Reilly & Associates |isbn=0-596-00467-2
*cite book |last=Goodman |first=Danny |coauthors=Eich, Brendan |title=JavaScript Bible |year=2001 |publisher=John Wiley & Sons |isbn=ISBN 0-7645-3342-8
*cite book |last=Watt |first=Andrew H. |coauthors=Watt, Jonathan A.; Simon, Jinjer L. |title=Teach Yourself JavaScript in 21 Days |year=2002 |publisher=Pearson Education |isbn=0-672-32297-8
*cite book |last=Duffy |first=Scott |title=How to do Everything with JavaScript |year=2003 |publisher=Osborne |isbn=0-07-222887-3
*cite book |last=Harris |first=Andy |title=JavaScript Programming for the Absolute Beginner |year=2001 |publisher=Premier Press |isbn=0-7615-3410-5
*cite book |last=Burns |first=Joe |coauthors=Growney, Andree S. |title=JavaScript Goodies |year=2001 |publisher=Pearson Education |isbn=0-7897-2612-2
*cite book |last= Shelly |first=Gary B. |coauthors=Cashman, Thomas J.; Dorin, William J.; Quasney, Jeffrey J. |title=JavaScript: Complete Concepts and Techniques |year=2000 |publisher=Course Technology |location=Cambridge |isbn=0-7895-6233-2
*cite book |last=Heinle |first=Nick |coauthors=Koman, Richard |title=Designing with JavaScript |year=1997 |publisher=O'Reilly & Associates |isbn=1-56592-300-6
*cite book |last=Bhangal |first=Sham |coauthors=Jankowski, Tomasz |title=Foundation Web Design: Essential HTML, JavaScript, CSS, PhotoShop, Fireworks, and Flash |year=2003 |publisher=APress L. P. |isbn=1-59059-152-6
*cite book |last=Vander Veer |first=Emily A. |title=JavaScript For Dummies |edition=4th Edition |year=2004 |publisher=Wiley Pub. |isbn=0-7645-7659-3
*cite book |last=Powell |first=Thomas A. |coauthors=Schneider, Fritz |title=JavaScript: The Complete Reference |year=2001 |publisher=McGraw-Hill Companies |isbn=0-07-219127-9External links
* Mozilla Developer Center
** [http://developer.mozilla.org/en/docs/JavaScript Mozilla's Official Documentation on JavaScript]
** References for Core JavaScript versions: [http://developer.mozilla.org/en/docs/Core_JavaScript_1.5_Reference 1.5]
** New in JavaScript: [http://developer.mozilla.org/en/docs/New_in_JavaScript_1.6 1.6] , [http://developer.mozilla.org/en/docs/New_in_JavaScript_1.7 1.7] , [http://developer.mozilla.org/en/docs/New_in_JavaScript_1.8 1.8]
** List of JavaScript releases: versions [http://developer.mozilla.org/en/docs/Core_JavaScript_1.5_Reference:About 1.5 - 1.8]
** [http://developer.mozilla.org/en/docs/A_re-introduction_to_JavaScript Re-Introduction to JavaScript]
*
* [http://eloquentjavascript.net/ Eloquent JavaScript] : "An opinionated guide to programming", with online interpreter
* [http://www.computerworld.com.au/index.php/id;243672124;fp;4194304;fpid;1 Computerworld Interview with Brendan Eich on JavaScript]
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