Logo         Community
The Company
Your Account
Contact Us
DTML Basics (part 2)
Find out more about DTML's conditional expressions and comparison operators

| If Only... |

The first - and simplest - decision-making routine is the "if" statement, which generally looks like this:

<dtml-if id>
do this!

The "condition" here refers to a conditional expression, which evaluates to either true or false.

Let's look at a piece of code to understand this better. Here's a DTML Method named "ifOnly", created in the same "DTML Basics" folder I used last time.

<dtml-if id>
<p>Variable "id" exists and has the value <dtml-var id>.</p>

<dtml-if myName>
<p>Variable "myName" exists and has the value "<dtml-var myName>".</p>

Now, when you view the output of this Method, you should see the following:

''.preg_replace(array('/  /', '/ /'), array('  ', '   '), '
Variable "id" exists and has the value DTML Basics.

If you take a close look at the code above, you'll see that it includes two "if" statements; however, only one is displayed in the output. This is because the first statement evaluated to a true value, because the variable "id" exists and has a value (the name of the container within which the DTML Method is stored). However, the second DTML variable "myName" does not exist. As a result, the corresponding "if" statement evaluates as false, and so, the text enclosed within the <dtml-if> block is not displayed.

How to do Everything with PHP & MySQL
How to do Everything with PHP & MySQL, the best-selling book by Melonfire, explains how to take full advantage of PHP's built-in support for MySQL and link the results of database queries to Web pages. You'll get full details on PHP programming and MySQL database development, and then you'll learn to use these two cutting-edge technologies together. Easy-to-follow sample applications include a PHP online shopping cart, a MySQL order tracking system, and a PHP/MySQL news publishing system.

Read more, or grab your copy now!

previous page more like this  print this article  next page
In trog...
Logging With PHP
Building A Quick-And-Dirty PHP/MySQL Publishing System
Output Buffering With PHP
Date/Time Processing With PHP
Creating Web Calendars With The PEAR Calendar Class
In the hitg report...
Crime Scenes
Animal Attraction
Lord Of The Strings
In boombox...
Patience - George Michael
Think Tank - Blur
My Private Nation - Train
In colophon...
Hostage - Robert Crais
The Dead Heart - Douglas Kennedy
Right As Rain - George Pelecanos
In cut!...
American Chai
The Core
Find out how you can use this article on your own Web site!

Copyright © 1998-2018 Melonfire. All rights reserved
Terms and Conditions | Feedback