PHP Tutorials - Herong's Tutorial Examples - v5.17, by Herong Yang
PHP Script Processing Rules
This section describes the PHP script source code processing rules - all non-PHP text segments are converted into print statements and merged with PHP code segments to form a single code block.
As I mentioned in the previous section, a PHP script source code is a sequence non-PHP text segments and PHP code segments. The PHP engine will process the source code in 3 logical steps:
In other words, a PHP script source code can be viewed as a single PHP code block. All non-PHP text segments are just PHP print statements written in a special way.
PHP's processing rules are very similar to Active Server Page (ASP)'s processing rules.
Now let's see an example PHP script source code file:
<?php /* HeadOrTail.php #- Copyright 2003 (c) HerongYang.com. All Rights Reserved. */ ?> I am tossing a coin now. Guess what the result will be? <?php $coin = rand(0,1); ?> <?php if ($coin==1) { ?> Head <?php } else { ?> Tail <?php } ?>
If you process this script with the PHP engine, you will get:
herong> \php\php HeadOrTail.php I am tossing a coin now. Guess what the result will be? Tail
Based on the PHP engine processing rules, the above script is identical to this script from the PHP engine process point of view:
<?php /* HeadOrTailModified.php #- Copyright 2003 (c) HerongYang.com. All Rights Reserved. */ print "I am tossing a coin now. Guess what the result will be?\n"; $coin = rand(0,1); if ($coin==1) { print " Head\n"; } else { print " Tail\n"; } ?>
Table of Contents
Introduction and Installation of PHP
PHP Script Source Code File Format
PHP Statement Delimiter and Comments
PHP Data Types and Data Literals
Variables, References, and Constants
Expressions, Operations and Type Conversions
Conditional Statements - "if" and "switch"
Loop Statements - "while", "for", and "do ... while"
Function Declaration, Arguments, and Return Values
Interface with Operating System
Introduction of Class and Object
Integrating PHP with Apache Web Server
Retrieving Information from HTTP Requests
Creating and Managing Sessions in PHP Scripts
Sending and Receiving Cookies in PHP Scripts
Controlling HTTP Response Header Lines in PHP Scripts
MySQL Server Connection and Access Functions
Functions to Manage Directories, Files and Images
SOAP Extension Function and Calling Web Services
SOAP Server Functions and Examples
Localization Overview of Web Applications
Using Non-ASCII Characters in HTML Documents
Using Non-ASCII Characters as PHP Script String Literals
Receiving Non-ASCII Characters from Input Forms
"mbstring" Extension and Non-ASCII Encoding Management
Managing Non-ASCII Character Strings with MySQL Servers
Parsing and Managing HTML Documents
Configuring and Sending Out Emails
Managing PHP Engine and Modules on macOS