1. Basic php

2. Php Official site: www.php.net PhP manual: http://www.php.net/manual/en/index.php Useful package (Apache, MySql,PhP): http://www.easyphp.org/

3. Where ? Ssh into cobweb.seas.gwu.edu and put your php files. Make sure they are readable by everyone. Access them via http://www.student.seas.gwu.edu/~yourus ername/filename.php http://www.student.seas.gwu.edu/~yourus ername/filename.php

4. What is PhP “PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML” (www.php.net) Server scripting language (Javascript is a client side scripting language) If you know C, you will learn PhP in no time.

5. Hello World! Index.php: PHP Test Hello World '; ?> Output : PHP Test Hello World

6. Basics Use echo for printing Variables start with $ sign Do not have to explicitly assign them a type (like int, array, etc.) If $x=3 and $a=’x’, echo $$a will display 3, because $$a=$($a)=$x=3;. (dot) concatenates 2 strings. Ex $a=”Hello”;$b=”World”; echo $a.” ”.$b; displays ”Hello World”

7. Accesing databases from PhP PHP Test <?php $link=mysql_connect("localhost",“username",“password") or die("Error connecting to the database server:".mysql_error()." \n"); mysql_select_db(“username") or die("Error selecting the database:".mysql_error()." \n"); ?> <?php $sql = "SELECT fname, sid FROM students;"; $result=mysql_query($sql); while(list($name,$id) = mysql_fetch_array($result)) { echo " ".$name." ".$id; } ?>

8. Arrays A mapping between keys and values. Example "bar", 12 => true); echo $arr["foo"]; // bar echo $arr[12]; // 1 foreach ($arr as $key => $value) { echo “key=”.$key; echo “ value=”,$value.” ”; } ?>

9. Get and Post $_GET[’variablename’] – the variable is appended to the http address, and is transmited in the same stream. Ex: http://www.somesite.com/index.php?a=1& b=’x’. Easy to bookmark $_POST[’variablename’] – a new stream is created, and all the post variables are transmited in this stresm. The http address is clean (no bookmarks)

10. Get variables from forms getName.html Your name: Your age: Action.php Exercise: try it with “get” now.

11. Some usefull global variables $_SERVER[’PHP_SELF’]- The filename of the currently executing script, relative to the document root. For instance, $_SERVER['PHP_SELF'] in a script at the address http://example.com/test.php/foo.bar would be /test.php/foo.bar. $_SERVER['SERVER_NAME']- The name of the server host under which the current script is executing. If the script is running on a virtual host, this will be the value defined for that virtual host. $_SESSION - An associative array containing session variables available to the current script. __LINE__ The current line number of the file. __FILE__ The full path and filename of the file. If used inside an include, the name of the included file is returned.

12. Session HTTP is stateless Simulates a statefull connection. Maintains records on the server side until the browser is closed. session_start(); $_SESSION[‘foo’]=‘bar’; $_SESSION[‘a’][‘b’]=‘c’; Allows to build a ”shoping cart”;

13. Includes header.php PHP Test footer.php index.php <?php include ”header.php”; echo ”hello world”; include ”footer.php” ?>