PHP3 Introduction - Getting your feet wet (
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Again, PHP3.0 commands can be easily inserted
alongside HTML. This provides an easy way to incorporate dynamic information
within what was previously a static document. For example, if we would like to
insert the current date into the HTML document that visitor has called, we might
do the following:
<HTML>
<HEAD>
<TITLE>Our first PHP3.0 script</TITLE>
</HEAD>
<BODY>
<CENTER>Our first PHP3.0 script</CENTER>
<?
/* the above "<?" signals that the PHP script has begun */
$today = date("Y-m-d");
PRINT "<CENTER>Today is: $today.</CENTER>";
# the following "?>" closes the script
?>
</BODY>
</HTML>
Assuming today is August 27, 1998, our output would be:
Our first PHP3.0 script
Today is: 1998-08-27.A
few points to make:
- All PHP3.0 commands must be enclosed within the "<?" and "?>"
brackets. A second method to denote PHP3.0 commands is by enclosing them within
"<?php...?>" brackets.
- Comments can be made within the script, and are enclosed within "/*" and
"*/" brackets, or by placing a "#" sign at the beginning of the line.
- All statements that are to be outputted to the screen must be enclosed in
double quotations ("), and led by the PRINT statement.
- Almost every PHP3.0 command must end in a semi-colon (;).
- Any HTML commands placed within the PRINT statements will be interpreted by
the browser, and perform their usual actions.
- Documents including PHP3.0 statements must be saved with the extension
*.php3 (For example, myphpfile.php3). This tells the PHP3.0 interpreter to
execute any commands found within the script.
- In short, the date command operates as follows:
Syntax: string
date(string format, int timestamp);
The function can take two
variables (timestamp) is optional. If supplied with a timestamp, the function
returns a string containing a date formatted according to the parameters within
the format string. In the above example, Y-m-d signifies year, month, and day,
respectively, all in numerical format. There are many other format characters
that can be placed within the format string. For a complete list, click here.
The include
statementAnother very powerful use of PHP3.0 is the capability of
building HTML templates, which are very useful when one is developing a cohesive
site with many pages. Let's assume one would like to place a footer at the
bottom of each page, for example:
Copyright ©
1997-99 . All rights
reserved.But what happens when the site increases in
size to say 50 pages, and suddenly the footer must include another statement?
This would involve the modification of each page, one by one, taking up a lot of
time and effort.
However, PHP3.0 offers the include statement, which
allows one to include a separate file within an HTML document. Let's insert the
above copyright statement into a separate text file, and save it as
"footer.txt". Then, one only has to insert the following command at the bottom
of the HTML file:
<? include("footer.txt")?>
and the footer will appear when loaded into the browser! Supposing the
site grows to 50 pages, and that copyright needs to be modified. The only step
the developer has to take is to open the footer file, make the necessary
modification, and Voila!. 50 pages are immediately updated.
Interesting,
huh? Now, let's look at some of the more dynamic aspects of the language,
incorporating HTML forms and variables passing/modification.
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