Programming Languages for Web Designers

Programming Languages for Web Designers
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CGI, JavaScript and Perl

CGI – Common Gateway Interface: not a language but a standard protocol developed to allow web pages to send information to each other. It defines the syntax used by arguments and environment variables passed on by web pages – typically those collected by forms – so that the pages at the receiving end know what to expect. The programs which actually process these variables may be written in any of the languages below:

JavaScript/JScript/VBScript – three variants of a simple scripting system which is handled by the client software – in other words, interpreted and run within the user’s own browser. JavaScript was the original, renamed from Mocha to make it sound like the Java programming language, though the two have little in common. VBScript and Jscript are proprietary scripting languages from Microsoft which closely resemble JavaScript in syntax and functionality. JavaScript is relatively easy to learn and use, although it lacks the power of the languages described below. Its best feature is that it will work on any site via code embedded in a standard web page. Its worst features are a) the user can turn it off and b) it has no long-term storage capabilities.

Perl – no acronym, just a variation of ‘Pearl’. Developed by Larry Wall in 1987 and developed extensively since, Perl is a high-level general-purpose interpreted programming language originally developed for producing complex reports, but now rarely used outside the Web. Perl has a strong core of support but is less widely used now that more specifically web-focused languages like PHP and ASP have become popular. Its very flexibility, with the inclusion of non-standard features like list handling, make it fairly intimidating for novices.

PHP and ASP

PHP – recursive acronym for PHP Hypertext Processor. PHP is an open-source interpreted server-side language; that is, it requires the web host to have PHP handling installed on the ‘back end’ of the site. This is fairly common, however, especially among paid hosts. PHP syntax is scary, with a liberal use of dollar signs, question marks, brackets, semicolons and other punctuation characters, but once this is mastered the language itself is not too difficult. PHP normally runs on web pages given a .php extension, where it may appear in functional blocks or be interspersed through HTML code in the body of the page. PHP applications tend to be constructed out of many small interlinked files, each with a specific purpose. Many free blogging and content-management systems such as Joomla! and Drupal are written in PHP.

ASP and ASP.NET. ASP (Active Server Pages) is Microsoft’s answer to PHP – a server-side interpreter designed for web form handling and database management. The syntax is equally forbidding, and in order to run ASP a web host must pay a licence fee to Microsoft, which makes ASP servers rarer and more expensive than their PHP equivalents. ASP.NET is a compiled version of the language released as part of Microsoft’s move to a global ‘.NET framework’.

Java and C

Java – once the great white hope of the Internet, Java is a complex object-oriented compiled language used to produce functional chunks of binary code called ‘applets’ which can be embedded in web pages. Originally appearing in 1995, Java was widely hyped as a platform-neutral system which would allow programs to run in a range of environments without modification, but its slow performance and user-unfriendly syntax disappointed many would-be users, and much of its audience was stolen by friendlier programming environments like Macromedia (now Adobe) Flash. Recent improvements in speed and programmer-friendliness may see Java re-emerge as a contender.

C and C++ – for better or worse, C has become the basis of most industry-standard programming environments, and new languages like JavaScript tend to borrow its syntax and structure even when they avoid most of its complexities. Outside the Microsoft Office desktop environment where Visual Basic prevails, C and C++ are almost ubiquitous. C is irritatingly complicated, with bizarre syntax, and it takes nothing for granted, but it is blindingly fast, and that is what counts – particularly on the web, where many factors operate to slow things down. C is the basic ‘vanilla’ version; C++ a widely-used object-oriented version developed in the late 1970s.

Flash ActionScript – with no particular goals of world domination in mind, Macromedia managed to develop an application which took the Web world by storm. Over the fourteen years since its development, the Flash environment – now maintained by Adobe – has provided an increasingly sophisticated set of options and controls which can be used to add motion and interactivity to web pages. ActionScript is the Flash scripting language, loosely based on JavaScript, which provides control over the timing of events and processes the user’s responses. With the aid of ActionScript, Flash programmers can produce rich and complex games and other embedded elements.

That ought to keep you busy for a while, anyway…