2. Agenda
● PHP HTML Embedding Tags and Syntax
● Simple PHP Script Example
● PHP and HTTP Environment Variables
3. PHP HTML Embedding Tags and
Syntax
● HTML is written as <tag>content<tag>
● Similarly, PHP Tags can be written as:
<?php method; ?>
e.g. <?php echo ”Hello World!”; ?>
● So how does it makes sense?
- Use different methods to generate contents
dynamically
- Call PHP functions and get results at run-
time
4. Some other ways to achieve the
same
● SGML Style (we have already seen!)
<?php echo ”Hello World!”; ?>
● ASP / JSP Style
<% echo “Hello World!”; %>
OR (Shortcut)
<p><?=”Hello World!”; ?>
● (Java)Script Style
<script language = “php”>
echo “Hello World!”;
</script>
5. Simple PHP Script Example
● A sample program that illustrates different
ways to code PHP!
<html>
<head><title><? Echo “This is a sample PHP
page!”; ?></title></head>
<body>
<h2>A math example</h2>
<p>10 + 11 = <%= 10+11 %>
<br/>and 8 + 9 = <% echo(8+9); %>
</body>
</html>
6. PHP and HTTP Environment
Variables
● HTTP as a protocol is different, in PHP it has
rich set of Global / environment variables.
● They are accessible globally!
● $HTTP_GET_VARS or $_GET
● $HTTP_POST_VARS or $_POST
● $HTTP_COOKIE_VARS or $_COOKIE
● $HTTP_SERVER_VARS or $_SERVER
● $HTTP_ENV_VARS or $_ENV
● $HTTP_POST_FILES
7. PHP and HTTP Environment
Variables - 1
● $HTTP_GET_VARS
&
$HTTP_POST_VARS
● Mostly used in GET and POST requests
respectively.
● Contains request information / data.
● Useful in form processing.
8. PHP and HTTP Environment
Variables - 2
● $HTTP_COOKIE_VARS
● Cookie is a very small, temporary text file
● A way of session management
● Stored and retrieved user specific information on
client
9. PHP and HTTP Environment
Variables - 3
● $HTTP_SERVER_VARS
● Various information about server
● Examples:
SERVER_SOFTWARE “wamp”
SERVER_NAME “www.sachinism.com”
SERVER_PROTOCOL “HTTP/1.1”
SERVER_PORT “80”
REQUEST_METHOD “POST”
QUERY_STRING “nm=hussu+age=32”
REMOTE_HOST “hostname_machine”
REMOTE_ADDR “192.168.10.1”
AUTH_TYPE “basic”
CONTENT_TYPE “x-url-encoded”
10. PHP and HTTP Environment
Variables - 4
● $HTTP_ENV_VARS
● Related to accessing machine and OS specific
environment variables
● $HTTP_POST_FILES
● Related to file upload
11. Summary
● PHP can be written in either of 3 ways,
SGML, Script or ASP / JSP styles.
● PHP environment variables like $_GET,
$_POST, $_COOKIE, $_SERVER provides
access to data stored in different ways like
sent as request, stored as cookies, or some
data about server.
12. Whats next?
● Learning language in dept...
● Variables, Constants and Data Types, and Op-
erators
● Decision Making, Flow Control and Loops
