Basic Java. Script | Java Script programming tutorial. Path // www. yourhtmlsource. Java. Script → BASIC JAVASCRIPTJava. Script is a very easy way to add all sorts of dynamic elements to your site. Unless you've had some programming experience, Java. Script will be quite a new concept at the start — it's fairly different to HTML. In this tutorial we'll be laying some groundwork on the language, and writing our first script. Page Navigation: What is Java. Script? · The Java Connection. Implementation. · External Scripts. A Simple Script. · < noscript> This page was last updated on 2. What is Java. Script? Java. Script is a simple scripting language invented specifically for use in web browsers to make websites more dynamic. On its own, HTML is capable of outputting more- or- less static pages. Once you load them up your view doesn't change much until you click a link to go to a new page. Adding Java. Script to your code allows you to change how the document looks completely, from changing text, to changing colours, to changing the options available in a drop- down list (and much, much more!). Mon Oct 18 20:53. These are simple Javascript programs, most shown in class. If you read them and (much better) play with variations, it will help you to. JavaScript Coding examples. A basic introduction to some of the techniques. Excellent! Magic Image Rotation. Can thank the author enough for this simple, yet powerful banner rotator. More grease to your el. Reviewer. Java. Script is a client- side language, which means all the action occurs on the client's (reader's) side of things. This means that no trips to the server are required for Java. Scripts to kick into operation, which would slow down the process enormously. Java. Script operations are usually performed instantaneously. In fact, Java. Script is often used to perform operations that would otherwise encumber the server, like form input validation. This distribution of work to the relatively quick client- side service speeds up the process. Java. Scripts are integrated into the browsing environment, which means they can get information about the browser and HTML page, and modify this information, thus changing how things are presented on your screen. This access to information gives Java. Script great power to modify the browsing experience. They can also react to events, such as when the user clicks their mouse, or points to a certain page element. This is also a very powerful ability. Most importantly, Java. Script isn't overly tough to learn and use. It's a little technical, yes; but after just a few tutorials you'll have some useful scripts in your pages, and will have the knowledge necessary to modify and use the countless free scripts available across the web. Browser Compatibility Note: Java. Script is supported by Netscape 2+, Internet Explorer 3+, Opera 3+ and most of the other modern web browsers. Each new version of the main browsers has supported new generations of Java. Script commands, each more complex than the last. Script compatibility can still be a problem, as the language is not as standardised as HTML; but this is being worked on. Learn JavaScript syntax and coding conventions that web developers use to create interactive and dynamic websites while you create an online résumé for your portfolio. What is JavaScript? JavaScript is a simple scripting language invented specifically for use in web browsers to make websites more dynamic. On its own, HTML is capable. Create a simple HTML page. Create a page of HTML with title, level one heading, and perhaps a paragraph of text. Save the document and load it in your browser. Javascript Programming: Part 1 Basic concepts in programming: What is programming? In Part 1 of this series, our goal is to get you used to some of the concepts found. Save Load Share Show output Hide output. Links. Real emulators in JavaScript: Apple IIjs, Apple //jse, Apple2JS, and many more. The Java Connection. Understandably, Java. Script's connection with Java is regularly misunderstood. They are not the same thing.» Java, created by » Sun Microsystems, is a full computer programming language like C++, suitable for writing complete, large- scale programs. Java. Script, on the other hand, was created by » Netscape. It was based to some degree on Java — the syntax of the code is very similar — but it is very rarely used for anything outside of a browser. It was actually originally to be called 'Live Script', but Java's increasing popularity at the time made Netscape change the name for marketing reasons. A scripting language can be thought of as a lightweight programming language; one that can be interpreted by a browser without needing to be compiled first. The script is actually just some commands that the browser has to do. The two share many similarities. Most prominent of these is that they are both forms of Object- Oriented Programming, or OOP. This means that you work with small objects that are combined together to form larger objects. We'll get into that more in a minute. You may have heard of Java being used alongside HTML through things called applets. These small- scale applications can be embedded into pages for very advanced effects, but they aren't entirely practical, due to large file sizes and limited extra utility. Java. Script on the other hand, can be very useful. Versions. Like seemingly every tool we use to create our sites, Java. Script has been arriving in versions, ever since version 1. Netscape Navigator 2. In subsequent versions Java. Script graduated through versions 1. Microsoft made an attempt at JS 1. Internet Explorer 3, but it was bugged to bits and was very unreliable. Microsoft dubbed their version “JScript”. The latest generation of browsers have decent support for Java. Script 1. 3. Coders' dismay at the incompatibilities wrought by the two browsers' different levels of support eventually lead to a standardised version of Java. Basic Programs In Javascript For LoopScript, sometimes called ECMAScript, after its standardisers, the » ECMA. Modern browsers like IE8, Firefox and Safari have good support for this standard, and a lot of work has gone on recently to ensure that all browsers are operating on the same DOM.. The DOMThe DOM, or Document Object Model, is the framework that Java. Script works off. Remember how I said Java. Script is a form of Object- oriented programming? This concept means we can think of all the elements that go into making a page as objects. The document itself is an object, made up of other objects like forms, images and tables. Form objects are also made up of even more objects like text boxes and submit buttons. All of these objects have properties, with values that define their colour, their length etc. Java. Script can read these properties and modify them, or react to events that happen to the objects, instantly changing the object in the browser window. A script can respond to user interaction with the page or can run all by itself. Actions that your script performs on or with objects are called methods. These are functions built- into objects. Dealing with user- controlled events like clicks and mouse movement is accomplished through commands called event handlers. Together, these concepts form the basis of all Java. Script programming. The DOM allows you to access these page objects. As mentioned above, for years there has been a bad situation wherein the two major browsers supported different versions of the DOM. Netscape's DOM was not compatible with Microsoft's, and so DHTML (Dynamic HTML) pages written to perform in one browser would not function in another. Recently, the W3. C have standardised the model, creating the » DOM level 1. Rest easy however; unless you're planning on creating vast Java. Script- fuelled sites, this probably won't become an issue for you. Not yet anyway. We'll discuss the DOM in more depth in Objects and Properties. Implementation. So how are we going to get our Java. Script into our pages? Java. Script is written in the same way as HTML — in a text- editor. JS implementation is quite similar to CSS; you can link to outside files (with the file extension . HTML documents with the < script> tag. The usual choosing criteria apply — if you're using the same script on many pages, link to an external file; otherwise embed. We'll do our first example with an embedded script. This will simply print a line of text to the page.< script type="text/javascript">. Hello World!< /i> "). When you place that in your code the text Hello World will appear on your screen wherever you put it. Like so: Let's break this down a bit. The script tag encloses any script code you want to use. The type attribute we have in there alert the browser to the type of script it is about to deal with (there are others, like VBScript), and so helps it to interpret the code. The comments around the script code are there so that old browsers that don't understand the script tag won't display the code as text on the page. Any browser that can do Java. Script will disregard the comments. Also note that for Netscape's benefit, the end of the comment is itself commented out using a Java. Script comment (two forward- slashes to comment out the rest of the line). This stops errors from occurring in old versions of Netscape. External Scripts. To import scripts from external JS files, save the code in a text file with the . In this case the code would just be the document. Hello World!"); part (although this won't do much on its own). We then link to this document, in the page's < head> , with< script type="text/javascript". Now all of the methods and variables that are in that file are available to use in the page. We'll learn more about that in the next tutorial. Note that Java. Script Includes, like this, are not supported by Netscape 2 and Explorer 3. Also remember the end- tag. The usual abstraction benefits ensue: you can update that one script file and have all your pages change; and the script file is cached meaning it doesn't need to be downloaded again for each page that uses it. We should always place includes in the head so that the browser is ready to execute scripts when the user calls for them. If a user clicked a button that called for a script that the browser wasn't aware of yet, you'd get an error. Having them in the head means they're always ready before they're needed. A Simple Script. So what did our code above actually accomplish? Take another look at it. Hello World!< /i> "). We start by taking control of the document object, and use its write() method to output some text to the document. The text inside the double quotes is called a String, and this string will be added to the page. Simple, right? To use an object's methods or properties, we write the object's name, a dot, and then the method/property name. Each line of script ends with a semicolon. Java. Script isn't very forgiving; if you make any mistakes in typing this out, you'll get a script error, so code carefully. We'll do one more example before wrapping up for this tutorial. This script will create some HTML and text. Main Title< /h. Body< /p> ").
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