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Encyclopedia > JavaScript
JavaScript
Paradigm multi-paradigm
Appeared in 1995
Designed by Brendan Eich
Developer Netscape Communications Corporation, Mozilla Foundation
Typing discipline dynamic, weak, duck
Major implementations SpiderMonkey, Rhino, KJS, JavaScriptCore
Dialects JScript, JScript .NET
Influenced by Self (semantics)
C (syntax)
Scheme (functional features)
Perl (regular expressions)
Python (1.7 features)

JavaScript is a scripting language most often used for client-side web development. It is a dynamic, weakly typed, prototype-based language with first-class functions. Currently, "JavaScript" is an implementation of the ECMAScript standard. Image File history File links Mergefrom. ... Client-side JavaScript (CSJS) is JavaScript that runs on client-side, i. ... A programming paradigm is a paradigmatic style of programming (compare with a methodology, which is a paradigmatic style of doing software engineering). ... A multiparadigm programming language is a programming language that supports more than one programming paradigm. ... Year 1995 (MCMXCV) was a common year starting on Sunday (link will display full 1995 Gregorian calendar). ... Brendan Eich Brendan Eich (born 1964) is a computer programmer and creator of the JavaScript programming language. ... For other uses, see Software developer (disambiguation). ... Netscape Communications Corporation was the publisher of the Netscape Navigator web browser as well as many other internet and intranet client and server software products. ... The Mountain View office shared by the Mozilla Foundation and the Mozilla Corporation The Mozilla Foundation (abbreviated MF or MoFo) is a non-profit organization that exists to support and provide leadership for the open source Mozilla project. ... In computer science, a type system defines how a programming language classifies values and expressions into types, how it can manipulate those types and how they interact. ... In computer science, a type system defines how a programming language classifies values and expressions into types, how it can manipulate those types and how they interact. ... In computing, weak typing, when applied to a programming language, is used to describe how the language handles datatypes. ... Duck typing is a style of dynamic typing in which an objects current set of methods and properties determines the valid semantics, rather than its inheritance from a particular class. ... Look up Implementation in Wiktionary, the free dictionary. ... SpiderMonkey is the code name for the first ever JavaScript engine, written by Brendan Eich at Netscape Communications and later released as open source. ... Rhino is an open source JavaScript engine. ... KJS is KDEs JavaScript engine that was originally developed for the KDE projects Konqueror web browser by Harri Porten in 2000. ... JavaScriptCore is a framework developed by Apple that provides a JavaScript engine for Mac OS X. It, along with WebCore, make up WebKit. ... A dialect of a programming language is a (relatively small) variation or extension of the language that does not change its intrinsic nature. ... JScript is the Microsoft implementation of the ECMAScript scripting programming language specification. ... JScript . ... This article or section does not cite its references or sources. ... C is a general-purpose, block structured, procedural, imperative computer programming language developed in 1972 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system. ... Scheme is a multi-paradigm programming language. ... Wikibooks has a book on the topic of Perl Programming Perl is a dynamic programming language created by Larry Wall and first released in 1987. ... Python is a high-level programming language first released by Guido van Rossum in 1991. ... Scripting languages (commonly called script languages) are computer programming languages that are typically interpreted. ... Client/Server is a network application architecture which separates the client (usually the graphical user interface) from the server. ... In computer science, a dynamic programming language is a kind of programming language in which programs can change their structure as they run: functions may be introduced or removed, new classes of objects may be created, new modules may appear. ... In computing, weak typing, when applied to a programming language, is used to describe how the language handles datatypes. ... Prototype-based programming is a style of object-oriented programming in which classes are not present, and behaviour reuse (known as inheritance in class-based languages) is performed via a process of cloning existing objects that serve as prototypes. ... In computer science, a programming language is said to support first-class functions if it treats functions as first-class objects. ... ECMAScript is a scripting programming language, standardized by Ecma International in the ECMA-262 specification. ...


JavaScript was influenced by many languages and was designed to have a similar look to Java, but be easier for non-programmers to work with.[1] The language is best known for its use in websites (as client-side JavaScript), but is also used to enable scripting access to objects embedded in other applications.


Despite the name, JavaScript is essentially unrelated to the Java programming language; though both have a common debt to C syntax. The language was renamed from LiveScript in a co-marketing deal between Netscape and Sun in exchange for Netscape bundling Sun's Java runtime with their browser, which was dominant at the time. The key design principles within JavaScript are inherited from the Self programming language. “Java language” redirects here. ... C is a general-purpose, block structured, procedural, imperative computer programming language developed in 1972 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system. ... Netscape Communications (formally known as Netscape Communications Corporation and commonly known as Netscape), is an American computer services company, best known for its web browser. ... This does not adequately cite its references or sources. ...


"JavaScript" is a trademark of Sun Microsystems.[2] It was used under license for technology invented and implemented by Netscape Communications and current entities such as the Mozilla Foundation.[3] “(TM)” redirects here. ... Sun Microsystems, Inc. ... Netscape Communications (formally known as Netscape Communications Corporation and commonly known as Netscape), is an American computer services company, best known for its web browser. ... The Mountain View office shared by the Mozilla Foundation and the Mozilla Corporation The Mozilla Foundation (abbreviated MF or MoFo) is a non-profit organization that exists to support and provide leadership for the open source Mozilla project. ...

Contents

History and naming

Some JavaScript source code

JavaScript was originally developed by Brendan Eich of Netscape under the name Mocha, later LiveScript, and finally renamed to JavaScript. The change of name from LiveScript to JavaScript roughly coincided with Netscape adding support for Java technology in its Netscape Navigator web browser. JavaScript was first introduced and deployed in the Netscape browser version 2.0B3 in December of 1995. The naming has caused confusion, giving the impression that the language is a spinoff of Java and 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. [1] [2] Image File history File links Download high-resolution version (988x629, 16 KB) Author: Mike Horvath File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Download high-resolution version (988x629, 16 KB) Author: Mike Horvath File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Brendan Eich Brendan Eich (born 1964) is a computer programmer and creator of the JavaScript programming language. ... Netscape Navigator, also known as Netscape, was a proprietary web browser that was popular during the 1990s. ... An example of a Web browser (Mozilla Firefox) A web browser is a software application that enables a user to display and interact with text, images, videos, music and other information typically located on a Web page at a website on the World Wide Web or a local area network. ...


To avoid trademark issues, Microsoft named its implementation of the language JScript. JScript was first supported in Internet Explorer version 3.0, released in August 1996 and included Y2K compliant date functions, unlike those based on java.util.Date in JavaScript at the time. Microsoft Corporation, (NASDAQ: MSFT, HKSE: 4338) is a multinational computer technology corporation with global annual revenue of US$44. ... JScript is the Microsoft implementation of the ECMAScript scripting programming language specification. ... Windows Internet Explorer (formerly Microsoft Internet Explorer abbreviated MSIE), commonly abbreviated to IE, is a series of proprietary graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems starting in 1995. ... This article is about the millennial computer glitch. ...


Netscape submitted JavaScript to Ecma International for standardization resulting in the standardized version named ECMAScript.[4] Ecma International is an international, private (membership-based) standards organization for information and communication systems. ... ECMAScript is a scripting programming language, standardized by Ecma International in the ECMA-262 specification. ...


Language

Further information: JavaScript syntax

As of 2006, the latest version of the language is JavaScript 1.7. The previous version 1.6 corresponded to ECMA-262 Edition 3 like JavaScript 1.5, except for Array extras, and Array and String generics. ECMAScript, in simple terms, is a standardized version of JavaScript. The ECMA-357 standard specifies E4X, a language extension dealing with XML. The syntax of JavaScript is a set of rules that defines how a JavaScript program will be written and interpreted. ... 2006 is a common year starting on Sunday of the Gregorian calendar. ... ECMAScript is a scripting programming language, standardized by Ecma International in the ECMA-262 specification. ... ECMAScript is a scripting programming language, standardized by Ecma International in the ECMA-262 specification. ... ECMAScript for XML (E4X) is a programming language extension that adds native XML support to ECMAScript (which include ActionScript, DMDScript, JavaScript, JScript). ... The Extensible Markup Language (XML) is a general-purpose markup language. ...


JavaScript is a prototype-based scripting language with a syntax loosely based on C. Like C, the language has no input or output constructs of its own. Where C relies on standard I/O libraries, a JavaScript engine relies on a host environment into which it is embedded. There are many such host environment applications, of which the web browser is the best known example. The syntax of JavaScript is a set of rules that defines how a JavaScript program will be written and interpreted. ... A JavaScript engine (also known as JavaScript interpreter or JavaScript implementation) is an interpreter that interpretes JavaScript source code and executes the script accordingly. ...


Distinguishing Characteristics

What makes JavaScript different from most other languages is its use of prototypes instead of classes, and its use of associative arrays as fundamental building blocks. Within Javascript, objects and associative arrays are the same thing, so that the following two lines of code are equivalent: Prototype-based programming is a style of object-oriented programming in which classes are not present, and behaviour reuse (known as inheritance in class-based languages) is performed via a process of cloning existing objects that serve as prototypes. ... In computing, an associative array, also known as a map, lookup table, or dictionary, is an abstract data type very closely related to the mathematical concept of a function with a finite domain. ...

  o.x = 10; o["x"] = 10;  

The dot notation in Javascript is merely syntactic sugar. Additionally, associative arrays are used within JavaScript for the following purposes: Syntactic sugar is a term coined by Peter J. Landin for additions to the syntax of a computer language that do not affect its functionality but make it sweeter for humans to use. ...

this object
When a function is invoked on an object (e.g o.f()) or when a function is used as a constructor (e.g. o = new F()) then the object o can be referred to within the code using the this keyword.
global object (window object within web browsers)
All globally defined variables are merely properties stored on a globally held associative array.
local object
A temporary object is created each time a function is invoked, and is used to store any locally declared variables. Javascript has function level scoping rather than block level scoping as a consequence of this.
closed local object
Functions defined within other functions (inner functions) are created each time the outer function is invoked, and contain a reference to the local object of the outer function for that invocation, causing the local variable to continue to exist after the original function invocation is over — this is the mechanism behind closures within JavaScript.
arguments object
The parameters passed to a function when it is invoked are passed as a single array (not an associative array), accessible via the arguments keyword. Formal parameters defined within the function declaration make the code easier to read but are non-essential.

In computer programming, scope is an enclosing context where values and expressions are associated. ... In computer programming, scope is an enclosing context where values and expressions are associated. ... In computer science, a closure is a function that is evaluated in an environment containing one or more bound variables. ...

Use in Web pages

See also: Ajax (programming)

The primary use of JavaScript is to write functions that are embedded in or included from HTML pages and interact with the Document Object Model (DOM) of the page. Some simple examples of this usage are: AJAX redirects here. ... HTML, an initialism of Hypertext Markup Language, is the predominant markup language for web pages. ... Hierarchy of objects in an example HTML DOM - Document Object Model The Document Object Model (DOM) is a platform- and language-independent standard object model for representing HTML or XML and related formats. ...

  • Opening or popping up a new window with programmatic control over the size, position and 'look' 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 runs on the client rather than the 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 attempt to 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 seeks to exploit JavaScript's strengths. Dozens of pop-up ads covering a desktop. ... The word validation has several uses: In general, validation is the process of checking if something satisfies a certain criterion. ... A webform on a web page allows a user to enter data that is, typically, sent to a server for processing and to mimic the usage of paper forms. ... Rollover refers to a button as created by a web developer or web designer, found within a web page, used to provide interactivity between the user and the page itself. ... For other uses, see Gmail (disambiguation). ... // Ajax may refer to: Ajax the Great as a well known hero from the Trojan war and son of Telamon Ajax the Lesser son of the king of Locris, and another hero in the Trojan war Ajax (missionary), Arian missionary who converted the pagan Suevi c. ...


A minimal example of a Web page containing JavaScript (using HTML 5 syntax) would be: HTML 5 is the fifth major revision of the core language of the World Wide Web, HTML. HTML 5 expressed in XML is called XHTML 5. ...

 <!DOCTYPE html> <html> <head><title>simple page</title></head> <body> <script> document.write('Hello World!'); </script> <noscript> Your browser does not support JavaScript. </noscript> </body> </html> 

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. Web Interoperability means producing web pages viewable in standard compatible web browsers, various operating systems such as Windows, Macintosh and Linux and devices such as PC, PDA and mobile phone based on the latest web standards. ... For Wikipedias accessibility guideline, see Wikipedia:Accessibility. ... It has been suggested that W3C Markup Validation Service be merged into this article or section. ...


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.[5] 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.[6][7] 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 or mobile phone browser which cannot execute JavaScript,
  • have JavaScript execution disabled as a security precaution,
  • or be visually or otherwise disabled and use a speech browser

To 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. Look up Personal digital assistant in Wiktionary, the free dictionary. ... Fault-tolerance or graceful degradation is the property that enables a system (often computer-based) to continue operating properly in the event of the failure of (or one or more faults within) some of its components. ...


Security

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 the same origin policy or the sandbox. In computer security, a sandbox is a is a play item for little kids, suppliers and untrusted users. ... In computing, the same origin policy is an important security measure for client-side scripting (mostly JavaScript). ... In computing, the same origin policy is an important security measure for client-side scripting (mostly JavaScript). ... In computer security, a sandbox is a is a play item for little kids, suppliers and untrusted users. ...


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. In that example, the script can then access the banking application with the privileges of the victim, potentially disclosing secret information or transferring money without the victim's authorization. Cross-site scripting (XSS) is a type of computer security vulnerability typically found in web applications which allow code injection by malicious web users into the web pages viewed by other users. ... Cross-site request forgery, also known as one click attack or session riding and abbreviated as CSRF (Sea-Surf) or XSRF, is a kind of malicious exploit of websites. ... Cross-site scripting (XSS) is a type of computer security vulnerability typically found in web applications which allow code injection by malicious web users into the web pages viewed by other users. ... In computing, the same origin policy is an important security measure for client-side scripting (mostly JavaScript). ...


XSS vulnerabilities can also occur because of implementation mistakes by browser authors.[8].


XSS is related to, but not the same as, 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 legitimate HTTP cookies attached to the request. JavaScript hijacking is an important example of XSRF. Cross-site request forgery, also known as one click attack or session riding and abbreviated as CSRF (Sea-Surf) or XSRF, is a kind of malicious exploit of websites. ... ...


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).[9]

Obfuscated code is source code that is (usually intentionally) very hard to read and understand. ...

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 overflows. 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[10], Internet Explorer[11], and Safari.[12]


Plugins, such as video players, Macromedia Flash, and the wide range of ActiveX controls enabled by default in Microsoft Internet Explorer, may also have flaws exploitable via JavaScript, and have in the past.[13][14] 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.[15] // == Macromedia Flash == ==]] Using Macromedia Flash 8 (bundled in Studio 8) in Windows XP. Maintainer: Adobe Systems (formerly Macromedia) Latest release: 8 / September 30th, 2005 OS: Windows (no native Windows XP Professional x64 Edition support), Mac OS X, Linux (i386 only, via wine [1]) Use: Multimedia Content Creator License: Proprietary Website... ActiveX is Microsoft technology used for developing reusable object oriented software components. ...


Sandbox 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[16] and Firefox[17]. In Windows XP Service Pack 2, Microsoft tightened the rules on what JavaScript would be run with high privileges by Internet Explorer.[18]


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 (like VBScript) a theoretically viable vector for a Trojan horse, although JavaScript Trojan horses are uncommon in practice.[19] (See Windows Script Host.) “Windows” redirects here. ... VBScript (short for Visual Basic Scripting Edition) is an Active Scripting language developed by Microsoft. ... In the context of computer software, a Trojan horse is a program that installs malicious software while under the guise of doing something else. ... The Microsoft Windows Script Host (originally called Windows Scripting Host, but renamed for the second release) is distributed and installed by default on Windows 98 and later versions of Microsoft Windows. ...


Uses outside Web pages

Outside of the Web, JavaScript interpreters are embedded in a number of tools. Adobe Acrobat and Adobe Reader support JavaScript in PDF files. The Mozilla platform, which underlies several common web browsers, uses JavaScript to implement the user interface and transaction logic of its various products. JavaScript interpreters are also embedded in proprietary applications in order to provide scriptable interfaces. Dashboard Widgets in Apple's Mac OS X v10.4 and Yahoo! Widgets are implemented using JavaScript. Microsoft's Active Scripting technology supports the JavaScript-compatible JScript as an operating system scripting language. Tools in the Adobe Creative Suite, including Photoshop, Illustrator, Dreamweaver and InDesign, allow scripting through JavaScript. Adobe Systems (pronounced a-DOE-bee IPA: ) (NASDAQ: ADBE) (LSE: ABS) is an American computer software company headquartered in San Jose, California, USA. Adobe was founded in December 1982[1] by John Warnock and Charles Geschke, who established the company after leaving Xerox PARC in order to develop and sell... Adobe Acrobat is a family of application software by Adobe Systems. ... “PDF” redirects here. ... Mozilla was the official, public, original name of Mozilla Application Suite by the Mozilla Foundation, nowadays called SeaMonkey suite. ... Dashboard is an application for Apples Mac OS X v10. ... Mac OS X version 10. ... Yahoo! Widgets is a free application platform for Mac OS X and Microsoft Windows. ... Active Scripting (formerly known as ActiveX Scripting) is the technology used in Windows to implement component-based scripting support. ... JScript is the Microsoft implementation of the ECMAScript scripting programming language specification. ... Adobe Creative Suite is a collection of graphic design, video editing, and web development applications made by Adobe Systems. ... Photoshop redirects here. ... This article does not cite any references or sources. ... Macromedia Dreamweaver is a web design software application developed by Macromedia. ... Adobe InDesign is a desktop publishing (DTP) application produced by Adobe Systems. ...


An ECMAScript implementation called Qt Script for Applications is available with the Qt application development toolkit.[20] Qt Script for Applications (QSA) is scripting engine, addon to Qt toolkit. ... For other uses, see Qt. ...


The interactive music signal processing software Max/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. Alternate meanings: MAX Max is a graphical development environment for music and multimedia developed and maintained by San Francisco-based software company Cycling74. ...


The Java programming language, in version SE 6 (JDK 1.6), introduced the javax.script package, based on Mozilla Rhino. This allows Java applications to read, interpret and execute JavaScript scripts at run-time.[21] The Java developer can make objects and variables that are part of the host application available to the JavaScript code using a Bindings object. These aspects of the running application can then be accessed and manipulated at run-time from JavaScript in a similar manner to the way that client-side scripts access the DOM of a displayed page in a web browser.[22] Java is an object-oriented programming language developed by James Gosling and colleagues at Sun Microsystems in the early 1990s. ... Rhino is an open source JavaScript engine. ...


JavaScript OSA (JavaScript for OSA, or JSOSA), is a scripting language for Mac OS based on the Mozilla 1.5 JavaScript implementation, SpiderMonkey. It is a freeware component made available by Late Night Software. Interaction with the operating system and with third-party applications is scripted via a MacOS object. Otherwise, the language is virtually identical to the core Mozilla implementation. It was offered as an alternative to the more commonly used AppleScript language. JavaScript OSA, (originally JavaScript for OSA, abbreviated as JSOSA), is a freeware inter-process communication scripting language for the Macintosh computer. ... This article relates to both the original Classic Mac OS as well as Mac OS X, Apples more recent operating system. ... Mozilla was the official, public, original name of Mozilla Application Suite by the Mozilla Foundation, nowadays called SeaMonkey suite. ... SpiderMonkey is the code name for the first ever JavaScript engine, written by Brendan Eich at Netscape Communications and later released as open source. ... Late Night Software Ltd. ... AppleScript is a scripting language devised by Apple, Inc. ...


ActionScript, the programming language used in Adobe Flash, is another implementation of the ECMAScript standard. ActionScript is a scripting language based on ECMAScript, used primarily for the development of websites and software using the Adobe Flash Player platform (in the form of SWF files embedded into Web pages). ... Adobe Flash, or simply Flash, refers to both the Adobe Flash Player, and to the Adobe Flash Professional multimedia authoring program. ...


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.


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 the Document Object Model) it is useful to have access to a debugger for each of the browsers a web application is being targeted at. A debugger is a computer program that is used to test and debug other programs. ... Hierarchy of objects in an example HTML DOM - Document Object Model The Document Object Model (DOM) is a platform- and language-independent standard object model for representing HTML or XML and related formats. ...


Currently, Internet Explorer, Firefox, and Safari all have script debuggers available for them. Opera announced a debugging developer tool in a preview released in February 2007. Windows Internet Explorer (formerly Microsoft Internet Explorer abbreviated MSIE), commonly abbreviated to IE, is a series of proprietary graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems starting in 1995. ... Firefox may refer to: Firefox (novel), written by Craig Thomas, published in 1978 Firefox (film), the 1982 movie starring Clint Eastwood, based on the novel Firefox (arcade game), the laserdisc arcade game based on the movie Mozilla Firefox, a web browser The Red Fox or the Red Panda, based on... Safari is a web browser developed by Apple Inc. ... Opera is a cross-platform web browser and Internet suite which handles common Internet-related tasks including visiting web sites, sending and receiving e-mail messages, managing contacts, chatting online, viewing Widgets, downloading BitTorrents, and reading Newsfeeds. ...


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 of Microsoft Office[23]), and finally the free Microsoft Script Debugger which is far more basic than the other two. Web applications within Firefox can be debugged using the Firebug plug-in, or the older Venkman debugger, which also works with the Mozilla browser. A debugger for the engine powering Apple's Safari, Webkit is also available under the name Drosera. Microsoft Visual Studio is Microsofts flagship software development product for computer programmers. ... Microsoft Office is an office suite from Microsoft for Microsoft Windows and Apple Mac OS X operating systems. ... Microsoft Script Debugger is a lightweight JScript debugger provided for free of charge. ... Firebug 1. ... Venkman is the JavaScript debugger component of the Mozilla web browser. ... Mozilla was the official, public, original name of Mozilla Application Suite by the Mozilla Foundation, nowadays called SeaMonkey suite. ... Safari is a web browser developed by Apple Inc. ... WebKit is an application framework included with Mac OS X v10. ... Drosera is a debugger included with the nightly builds of Safari/WebKit. ...


There are also some free tools such as JSLint and JavaScriptLint, which will scan JavaScript code looking for problems,[24] as well as a non-free JavaScript Debugger called SplineTech JavaScript 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.


Each script block is parsed separately. On web pages where JavaScript in script blocks is mixed with HTML, syntax errors can be identified more readily by keeping discrete functions in separate script blocks, or (for preference), using many small linked .js files. This way, a syntax error will not cause parsing/compiling to fail for the whole page, which can help to allow a graceful exit. A graceful exit is a simple programming idiom wherein a program detects a serious error condition and exits gracefully in a controlled manner as a result. ...


Related languages

There is no 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 variables and members are statically typed, whereas all JavaScript variables (as well as object properties and array elements) may hold a value of any type. In computer science, a type system defines how a programming language classifies values and expressions into types, how it can manipulate those types and how they interact. ...


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. ECMAScript is a scripting programming language, standardized by Ecma International in the ECMA-262 specification. ...


Microsoft's own VBScript, like JavaScript, can be run client-side in web pages. VBScript has syntax derived from Visual Basic and will only run if the web pages are viewed in Internet Explorer. VBScript (short for Visual Basic Scripting Edition) is an Active Scripting language developed by Microsoft. ... This article is about the Visual Basic language shipping with Microsoft Visual Studio 6. ...


JSON, or JavaScript Object Notation, is a general-purpose data interchange format that is defined as a subset of JavaScript. JSON (JavaScript Object Notation) (Pronounced like Jason, IPA ) is a lightweight computer data interchange format. ...


ECMAScript was included in the VRML97 standard for scripting nodes of VRML scene description files. VRML (Virtual Reality Modeling Language, pronounced vermal or by its initials, originally known as the Virtual Reality Markup Language) is a standard file format for representing 3-dimensional (3D) interactive vector graphics, designed particularly with the World Wide Web in mind. ...


JavaScript is also considered a functional programming language like Scheme and OCaml because it has closures and supports higher-order functions.[25] Functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. ... Scheme is a multi-paradigm programming language. ... Objective Caml (OCaml) is a general-purpose programming language descended from the ML family, created by Xavier Leroy, Jérôme Vouillon, Damien Doligez, Didier Rémy and others in 1996. ... In computer science, a closure is a function that is evaluated in an environment containing one or more bound variables. ... In mathematics and computer science, higher-order functions are functions which can take other functions as arguments, and may also return functions as results. ...


See also

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Image File history File links Wikibooks-logo-en. ... Wikibooks logo Wikibooks, previously called Wikimedia Free Textbook Project and Wikimedia-Textbooks, is a wiki for the creation of books. ... Server-side JavaScript (SSJS) refers to JavaScript that runs on server-side. ... The syntax of JavaScript is a set of rules that defines how a JavaScript program will be written and interpreted. ... A JavaScript engine (also known as JavaScript interpreter or JavaScript implementation) is an interpreter that interpretes JavaScript source code and executes the script accordingly. ... JSDoc is a syntax for adding inline API documentation to JavaScript source code. ... The following is a list of ECMAScript engines. ... Dynamic HTML or DHTML is a collection of technologies used together to create interactive and animated web sites by using a combination of a static markup language (such as HTML), a client-side scripting language (such as JavaScript), a presentation definition language (Cascading Style Sheets, CSS), and the Document Object... LiveConnect is a programming interface. ... A single page application (SPA) is a web application that runs entirely in the client web browser, typically using a combination of HTML, JavaScript, and CSS. The application modifies the web pages own data structures through its DOM tree, and makes its changes persistent when the user invokes the... AJILE, pronounced Agile, is the Advanced JavaScript Importing & Loading Extension. ... JSON (JavaScript Object Notation) (Pronounced like Jason, IPA ) is a lightweight computer data interchange format. ... Wikipedia does not yet have an article with this exact name. ... AJAX redirects here. ... XMLHTTP is a set of APIs that can be used by JavaScript, JScript, VBScript and other web browser scripting languages to transfer and manipulate XML data to and from a web server using HTTP, establishing an independent connection channel between Client-Side and Server-Side. ... Unobtrusive JavaScript is an emerging paradigm in the JavaScript programming language, as used on the World Wide Web. ... This article provides basic feature comparison between some of the javascript-based source code editors available today. ...

Notes

  1. ^ http://wp.netscape.com/columns/techvision/innovators_be.html
  2. ^ Sun Trademarks. Sun Microsystems. Retrieved on 2007-11-08.
  3. ^ http://www.sun.com/suntrademarks/
  4. ^ http://cgi.netscape.com/newsref/pr/newsrelease289.html
  5. ^ Peter-Paul Koch, Object detection
  6. ^ Peter-Paul Koch, Mission Impossible - mouse position
  7. ^ Peter-Paul Koch, Browser detect
  8. ^ MozillaZine, Mozilla Cross-Site Scripting Vulnerability Reported and Fixed
  9. ^ For an exampleo f this bad practice, see http://javascript.internet.com/passwords/
  10. ^ Mozilla Corporation, Buffer overflow in crypto.signText()
  11. ^ Paul Festa, CNet, Buffer-overflow bug in IE
  12. ^ SecurityTracker.com, Apple Safari JavaScript Buffer Overflow Lets Remote Users Execute Arbitrary Code and HTTP Redirect Bug Lets Remote Users Access Files
  13. ^ SecurityFocus, Microsoft WebViewFolderIcon ActiveX Control Buffer Overflow Vulnerability
  14. ^ Fusion Authority, Macromedia Flash ActiveX Buffer Overflow
  15. ^ Mike Friedman, Protected Mode in Vista IE7
  16. ^ US CERT, Vulnerability Note VU#713878: Microsoft Internet Explorer does not properly validate source of redirected frame
  17. ^ Mozilla Foundation, Mozilla Foundation Security Advisory 2005-41: Privilege escalation via DOM property overrides
  18. ^ Microsoft Corporation, Changes to Functionality in Microsoft Windows XP Service Pack 2: Part 5: Enhanced Browsing Security
  19. ^ For one example of a rare JavaScript Trojan Horse, see Symantec Corporation, JS.Seeker.K
  20. ^ Trolltech ASA, Qt Script for Applications
  21. ^ http://java.sun.com/javase/6/webnotes/index.html#scripting javax.script release notes
  22. ^ Flanagan 5th Edition, Pp 214 et seq
  23. ^ http://msdn2.microsoft.com/en-us/library/aa202668(office.11).aspx JScript development in Microsoft Office 11 (MS InfoPath 2003)
  24. ^ http://www.jslint.com/lint.html JSLint help page
  25. ^ The Little JavaScripter shows the relationship with Scheme in more detail.

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 312th day of the year (313th in leap years) in the Gregorian calendar. ...

References

  • McDuffie, Tina Spain (2003). JavaScript Concepts & Techniques: Programming Interactive Web Sites. Franklin, Beedle & Associates. ISBN 1-887-90269-4. 
  • McFarlane, Nigel (2003). Rapid Application Development with Mozilla. Prentice Hall Professional Technical References. ISBN 0-13-142343-6. 
  • Flanagan, David; Ferguson, Paula (2002). JavaScript: The Definitive Guide, 4th Edition, O'Reilly & Associates. ISBN 0-596-00048-0. 
  • Flanagan, David (2006). JavaScript: The Definitive Guide, 5th Edition, O'Reilly & Associates. ISBN 0-596-10199-6. 
  • Goodman, Danny; Markel, Scott (2003). JavaScript and DHTML Cookbook. O'Reilly & Associates. ISBN 0-596-00467-2. 
  • Goodman, Danny; Eich, Brendan (2001). JavaScript Bible. John Wiley & Sons. ISBN ISBN 0-7645-3342-8. 
  • Watt, Andrew H.; Watt, Jonathan A.; Simon, Jinjer L. (2002). Teach Yourself JavaScript in 21 Days. Pearson Education. ISBN 0-672-32297-8. 
  • Powell, Thomas A.; Schneider, Fritz (2001). JavaScript: The Complete Reference. McGraw-Hill Companies. ISBN 0-07-219127-9. 
  • Duffy, Scott (2003). How to do Everything with JavaScript. Osborne. ISBN 0-07-222887-3. 
  • Harris, Andy (2001). JavaScript Programming for the Absolute Beginner. Premier Press. ISBN 0-7615-3410-5. 
  • Burns, Joe; Growney, Andree S. (2001). JavaScript Goodies. Pearson Education. ISBN 0-7897-2612-2. 
  • Shelly, Gary B.; Cashman, Thomas J.; Dorin, William J.; Quasney, Jeffrey J. (2000). JavaScript: Complete Concepts and Techniques. Cambridge: Course Technology. ISBN 0-7895-6233-2. 
  • Heinle, Nick; Koman, Richard (1997). Designing with JavaScript. O'Reilly & Associates. ISBN 1-56592-300-6. 
  • Bhangal, Sham; Jankowski, Tomasz (2003). Foundation Web Design: Essential HTML, JavaScript, CSS, PhotoShop, Fireworks, and Flash. APress L. P.. ISBN 1-59059-152-6. 
  • Vander Veer, Emily A. (2004). JavaScript For Dummies, 4th Edition, Wiley Pub.. ISBN 0-7645-7659-3. 
  • Powell, Thomas A.; Schneider, Fritz (2001). JavaScript: The Complete Reference. McGraw-Hill Companies. ISBN 0-07-219127-9. 

External links

  • Mozilla's Official Documentation on JavaScript
  • References for Core JavaScript versions: 1.5
  • New in JavaScript: 1.7, 1.6
  • List of JavaScript releases: versions 1.0 - 1.7
  • Basic Javascript, a basic Java Script programming tutorial by HTMLSource

  Results from FactBites:
 
The JavaScript Weblog (1761 words)
Using a Javascript syntax, developers can add their own functionality to the program to do several repetitive tasks with the click of a button, for example.
Using Javascript to utilize the scroll wheel a la Google maps is the new "cool guy" thing.
The JavaScript Weblog is a member of the Weblogs, Inc. Network.
JavaScript - Wikipedia, the free encyclopedia (2030 words)
Despite the name, JavaScript is only distantly related to the Java programming language, the main similarity being their common debt to the C programming language.
JavaScript is a registered trademark of Sun Microsystems, Inc., used under license for technology invented and implemented by Netscape.
Because JavaScript is interpreted, loosely-typed, and must run at the client-side in varying environments (host applications), implementations and versions the 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 nicely when it does not.
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