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Agenda
• What is PHP?
• How does PHP work?
• Servers
• Your first PHP page
• Execution
4. What is PHP?
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• PHP was originally an acronym for Personal Home Pages, but is
now a recursive acronym for PHP: Hypertext Pre-processor.
• PHP was originally developed by the Danish Greenlander
Rasmus Lerdorf, and was subsequently developed as open
source. PHP is not a proper web standard - but an open-source
technology.
• PHP is neither real programming language - but PHP lets you use
so-called scripting in your documents.
• To describe what a PHP page is, you could say that it is a file with
the extension .php that contains a combination of HTML tags and
scripts that run on a web server.
5. How does PHP work?
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The best way to explain how PHP works is by comparing it with
standard HTML. Imagine you type the address of an HTML
document (e.g. http://www.mysite.com/page.htm) in the address
line of the browser.
This way you request an HTML page. It could be illustrated like
this:
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As you can see, the server simply sends an HTML file to the client. But if
you instead type http://www.mysite.com/page.php - and thus request an
PHP page - the server is put to work:
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The server first reads the PHP file carefully to see if there are any tasks
that need to be executed. Only when the server has done what it is
supposed to do, the result is then sent to the client. It is important to
understand that the client only sees the result of the server's work, not
the actual instructions.
This means that if you click "view source" on a PHP page, you do not
see the PHP codes - only basic HTML tags. Therefore, you cannot see
how a PHP page is made by using "view source". You have to learn
PHP in other ways
8. Servers
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• PHP is a server-side technology. Therefore, you need to have a server to
run PHP. But it doesn't need to cost you anything to make this upgrade
and there are several options for doing so.
• Since you ultimately only need to choose one option, this is divided into
three parts. First comes a little introduction on the different options (just
choose the one that suits you best). When your server is up and running,
Option 1: Website on a hosted server
You can choose to have a website on a host that supports PHP.
Option 2: Install PHP on your computer
It's no walk in the park to install PHP on your computer. This option is only
recommend for experienced computer users, but it can obviously be done.
Here are links to downloads and installation
• Windows Installation
• Mac Installation
• Linux Installation
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Option 3: XAMPP
XAMPP is a program that makes it easy and possible for us ordinary
folks to run the PHP directly on our computer without having to install
PHP on our own.
10. Your first PHP page
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