What Is Javascript Used For? by Jim Pretin

If you are creating a web site for the second or third time, then you probably already have some experience with HTML. HTML is a fairly simple language to learn, and most new web designers learn to use it pretty quickly. HTML provides the style, structure, and formatting for a web page.

However, HTML does not actually do anything. It is a static programming language. It does not process information or make your site interactive, it just sits there and tells the web browser how the site should be displayed. So, other programming languages have been established to make websites interactive.

Of the non-static programming languages that are used to complement an HTML web page, Javascript is perhaps the most important. Contrary to its name, it has virtually nothing to do with the Java programming language. Javascript is a scripting language.

Scripting languages are used to connect diverse pre-existing parts to accomplish a new related task without compiling. Instead, scripting languages are interpreted, and are executed faster than a compiling language. Javascript is very versatile and can communicate with other languages effectively. It is a registered trademark of Sun Microsystems, and is compatible with every major browser on the market.

Javascript is most often used to handle certain events that might take place as the user interacts with the web page. For example, if the user is filling out an online form on the site and enters information that does not comply with a certain format, then Javascript can be utilized to check the format of the input before the form is submitted. If the input is invalid, the script can be used to prevent the form from being submitted and to tell the user what needs to be corrected.

When used, the script is ordinarily inserted in between the opening and closing head tags. In the head section, the programmer can create Javascript functions that can be executed if that function is called upon somewhere in the body of the page.

If a webpage contains an HTML form, the programmer may want to create a Javascript function to insure that the user enters his or her last name before the form can be submitted. To accomplish this, a function must be inserted in between the opening and closing head tags. Then, the function must be called upon within the opening tag of the HTML form.

Then, if someone attempts to submit the form, the Javascript function is called upon to make sure that the last name has been entered. If the last name has been omitted, then the submission is halted and the user is told to enter his or her last name before submitting the form.

The logic of these functions is often created using if/then statements. Uses for these functions include form validation, enabling cookies, displaying certain images when the user performs a certain action, and detecting what kind of web browser the user has so that the format of the web page can be adjusted to accommodate that particular browser.

Javascript is actually a fairly easily language to learn, because it is very logical and the syntax is not complicated. Even if you have never used it before, you can learn it fairly easily by searching for tutorials on a search engine. Using non-static programming languages will bring your web pages to life.

Author Resource: Jim Pretin is the owner of http://www.forms4free.com, a service that helps programmers make a free HTML form.

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