How to develop websites and program software – Free PC Service and Advice.
Programming is the process of writing instructions that tell computer hardware what to do. It’s fundamental to computing, yet to most people it’s an impenetrable and arcane art. It needn’t be a mystery, though. It would be ridiculous for us to suggest that non-programmers could soon be writing software to rival Microsoft Word or Excel, but understanding the basic principles isn’t as difficult as you might think.
If you’ve never dabbled in computer programming, here’s your opportunity to gain an appreciation of what’s involved. In the first of a two-part series, we’ll teach you the fundamentals so you can start writing programs for your PC.
Many programming languages are available; here, we’ve used Basic (short for beginners’ all-purpose symbolic instruction code). We chose this language for its relative simplicity. All you need to know before you begin is the definition of a program: a list of instructions that is carried out sequentially and tells the computer what to do.
The Language of the world wide web
CSS is designed primarily to enable the separation of document content from document presentation, including elements such as the layout, colors, and fonts. This separation can improve content accessibility, provide more flexibility and control in the specification of presentation characteristics, enable multiple HTML pages to share formatting by specifying the relevant CSS in a separate .css file, and reduce complexity and repetition in the structural content, such as semantically insignificant tables that were widely used to format pages before consistent CSS rendering was available in all major browsers. CSS makes it possible to separate presentation instructions from the HTML content in a separate file or style section of the HTML file. For each matching HTML element, it provides a list of formatting instructions. For example, a CSS rule might specify that “all heading 1 elements should be bold”, leaving pure semantic HTML markup that asserts “this text is a level 1 heading” without formatting code such as a <bold> tag indicating how such text should be displayed.
This separation of formatting and content makes it possible to present the same markup page in different styles for different rendering methods, such as on-screen, in print, by voice (when read out by a speech-based browser or screen reader) and on Braille-based, tactile devices. It can also be used to display the web page differently depending on the screen size or device on which it is being viewed. Although the author of a web page typically links to a CSS file within the markup file, readers can specify a different style sheet, such as a CSS file stored on their own computer, to override the one the author has specified. If the author or the reader did not link the document to a style sheet, the default style of the browser will be applied. Another advantage of CSS is that aesthetic changes to the graphic design of a document (or hundreds of documents) can be applied quickly and easily, by editing a few lines in one file, rather than by a laborious (and thus expensive) process of crawling over every document line by line, changing markup.
The CSS specification describes a priority scheme to determine which style rules apply if more than one rule matches against a particular element. In this so-called cascade, priorities (or weights) are calculated and assigned to rules, so that the results are predictable.
The CSS specifications are maintained by the World Wide Web Consortium (W3C). Internet media type (MIME type)
text/css is registered for use with CSS by RFC 2318 (March 1998). The W3C operates a freeCSS validation service for CSS documents.
is a core technology markup language of the Internet used for structuring and presenting content for the World Wide Web. As of October 2014 this is the final and complete fifth revision of the HTML standard of the World Wide Web Consortium (W3C). The previous version, HTML 4, was standardized in 1997.
Its core aims have been to improve the language with support for the latest multimedia while keeping it easily readable by humans and consistently understood by computers and devices (web browsers, parsers, etc.). HTML5 is intended to subsume not only HTML 4, but also XHTML 1 and DOM Level 2 HTML.
Following its immediate predecessors HTML 4.01 and XHTML 1.1, HTML5 is a response to the fact that the HTML and XHTML in common use on the World Wide Web are a mixture of features introduced by various specifications, along with those introduced by software products such as web browsers, those established by common practice. It is also an attempt to define a single markup language that can be written in either HTML or XHTML. It includes detailed processing models to encourage more interoperable implementations; it extends, improves and rationalizes the markup available for documents, and introduces markup and application programming interfaces (APIs) for complex web applications. For the same reasons, HTML5 is also a potential candidate for cross-platform mobile applications. Many features of HTML5 have been built with the consideration of being able to run on low-powered devices such as smartphones and tablets. In December 2011, research firm Strategy Analytics forecast sales of HTML5 compatible phones would top 1 billion in 2013.
In particular, HTML5 adds many new syntactic features. These include the new <video>, <audio> and <canvas> elements, as well as the integration of scalable vector graphics (SVG) content (replacing generic<object> tags), and MathML for mathematical formulas. These features are designed to make it easy to include and handle multimedia and graphical content on the web without having to resort to proprietary pluginsand APIs. Other new page structure elements, such as <main>, <section>, <article>, <header>, <footer>, <aside>, <nav> and <figure>, are designed to enrich the semantic content of documents. Newattributes have been introduced, some elements and attributes have been removed and some elements, such as <a>, <cite> and <menu> have been changed, redefined or standardized. The APIs and Document Object Model (DOM) are no longer afterthoughts, but are fundamental parts of the HTML5 specification. HTML5 also defines in some detail the required processing for invalid documents so that syntax errors will be treated uniformly by all conforming browsers and other user agents.
COMPUTER REPAIRS AND TROUBLE-SHOOTING
Do you know what to do if your screen goes blank? What if you can’t seem to close an application—or can’t hear any sound from your speakers? Whenever you have a problem with your computer, don’t panic! There are many basic troubleshooting techniques you can use to fix issues like this. In this lesson, we’ll show you some simple things to try when troubleshooting, as well as how to solve common problems you may encounter.
General tips to keep in mind
There are many different things that could cause a problem with your computer. No matter what’s causing the issue, troubleshooting will always be a process of trial and error—in some cases, you may need to use several different approaches before you can find a solution; other problems may be easy to fix. We recommend starting by using the following tips if you are having computer problems that need fixing.
- Write down your steps: Once you start troubleshooting, you may want to write down each step you take. This way, you’ll be able to remember exactly what you’ve done and can avoid repeating the same mistakes. If you end up asking other people for help, it will be much easier if they know exactly what you’ve tried already.
- Take notes about error messages: If your computer gives you an error message, be sure to write down as much information as possible. You may be able to use this information later to find out if other people are having the same error.
- Always check the cables: If you’re having trouble with a specific piece of computer hardware, such as your monitor or keyboard, an easy first step is to check all related cables to make sure they’re properly connected.
- Restart the computer: When all else fails, one of the best things to try is to restart the computer. This can solve a lot of basic issues you may experience with your computer.