JavaScript is a dynamic computer interpreted programming or dynamic script language from Netscape of HTML and the Web with object-oriented capabilities. It is lightweight and commonly used as a part of web pages, whose implementations allow a client-side script to interact with the user and create dynamic pages and performing various tasks. It is similar in capability to Microsoft’s Visual Basic, Sun’s TCL, the UNIX-derived Perl and IBM’s REXX.
Script languages are more popular than the more structured C and C++ languages. Some feel that coding is easier in script languages. The downside is that script languages take longer to process, and that makes them suitable for smaller programming needs.
In 1990 JavaScript was developed by Netscape and was originally named LiveScript. The popularity of Java prompted Netscape to rename it as JavaScript. Today, Netscape, Internet Explorer and most other browsers have embedded the general-purpose core the language.
Client-side JavaScript
It is the most common form of the language. The script should be included in or referenced by an HTML document for the code to be interpreted by the browser. The applied use eliminates the need for a static HTML page and allows web pages to include features that allow interaction with visitors, control of the browser functions and creation and rendering of dynamic content.
The client-side mechanism has many advantages over CGI server-side scripts. For instance, we are accustomed to taking email address validation while filling out a form for granted. This simple function is possible when executing a JavaScript code after someone submits the form – and even before submitting the form to the server.
Determining what happens after a user initiated actions like clicking on buttons, and navigation link can also be facilitated using JavaScript.
Today, for every web developer, the knowledge of three languages has become mandatory:
- HTML to define the content of web pages. HTML is meant for static web page content.
- CSS or (Cascading Style Sheets) for defining the layout and visual treatment on web pages.
- JavaScript the behavior of web pages. Sometimes the distinction between JavaScript and HTML is confusing because JavaScript code can go in the same file as HTML.
How to run JavaScript and how does it work?
Usually, JavaScript support is built into most major web browsers, including Internet Explorer, Firefox, and Safari. If the visitors to your site are using web browsers that support JavaScript and have JavaScript enabled by default, then it is likely to run automatically when a person visits the page. For a person to use JavaScript on their web page, there is no need to learn the whole process since there is plenty of pre-written JavaScript that has been made available to plug straight into the web page
It is an interpreted language and does not require any special program to create usable code. A plain text editor is sufficient to write JavaScript (Notepad). While editing, adding color to the code makes it easier to differentiate and easier to find mistakes.
PHP or Other Server-Side Language can sometimes be used instead of JavaScript, especially if the code can be executed before the page is rendered. However, if the code has to run after the page is loaded, then JavaScript should be used because it is the only client-side scripting language supported by most browsers.
While JavaScript can be included within the HTML file, the best practice is to externalize scripts and call them from .js files. This reduces the HTML file size and helps improve page load time. This also allows the same JavaScript file to be added to multiple pages that require the same functionality without adding the entire code to all the HTML files.
Advantages of JavaScript
- JavaScript is lightweight and interpreted programming language.
- It is designed to create network-centric applications.
- JavaScript is complementary and integrated with Java and HTML.
- This language is easy to learn and is an open and cross-platform.
- Fewer server calls.
- Form inputs from visitors are validated before submitting the page to the server, thereby reducing server load.
- Immediate feedback to visitors since they need not wait for the page to reload to check if they have forgotten to enter something.
- Increased interactivity as interfaces can be created to react when the user is dwelling on the page, hovering with the mouse or interacting through a keyboard.
- Richer interface to include items such as drag-and-drop components and sliders that provide a more sophisticated impression to the website.
Disadvantages of JavaScript
It cannot be considered a full-fledged programming language as it lacks the following important features:
- Client-side JavaScript does not allow reading or writing of files for security reasons.
- It cannot be used for networking applications because there is no support available.
- It does not have multi-threading or multi-processor capabilities.
JavaScript development tools
JavaScript does not require expensive development tools. It can even start with an editor as simple as Notepad. As in interpreted language, it does not require a compiler.
Some of the more popular JavaScript editing tools are listed here:
- Microsoft FrontPage.
- Macromedia Dreamweaver MX.
- Macromedia HomeSite 5.
- ECMAScript Edition 5 Standard.
The above information is a brief overview and outline of JavaScript as a language. It is straightforward and easy to understand or adapt since it does not have too many specifications or requirements. To better understand how it JavaScript useful for your business or website, you can contact Flying Cow for their professional expertise.
CEO, Flying Cow Design
Attended University of Auckland
Lives in San Francisco Bay Area