1 / 24

Introduction to PHP and Server Side Technology

Introduction to PHP and Server Side Technology. PHP History. Created in 1995 PHP 5.0 is the current version It’s been around since 2004. General PHP Characteristics. PHP is made up of a PHP scripting block PHP scripting blocks can appear anywhere in a Web page

cosima
Download Presentation

Introduction to PHP and Server Side Technology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to PHP and Server Side Technology

  2. PHP History • Created in 1995 • PHP 5.0 is the current version • It’s been around since 2004

  3. General PHP Characteristics • PHP is made up of a PHP scripting block • PHP scripting blocks can appear anywhere in a Web page • In addition to PHP scripting blocks, PHP documents typically contain XHTML • A page having embedded PHP script must have a file suffix of .php

  4. The Basics of PHP Syntax • PHP script always appears between • <?php and ?> • PHP statements always end in a semi-colon • Comments have the same format as JavaScript • PHP IS CASE SENSITIVE

  5. A First PHP Program • As in • <html> <body><?phpecho "Hello";?> </body></html>

  6. A First Server Round Trip Using Forms (1) • Remember form widgets from JavaScript <input type=“text”> and so on • Remember widgets are contained in a form • Widgets are visible from PHP script so we can process their contents to the server

  7. A First Server Round Trip Using Forms (2) • The following form posts to the page named Welcome.php (action attribute) <form action="welcome.php" method="post"> Name: <input type="text" name="fname" /> Age: <input type="text" name="age" /> <input type="submit" /> </form>

  8. A First Server Round Trip Using Forms (3) • Welcome.php contains the script to process the posted data <html> <body> Welcome <?php echo $_POST["fname"]; ?>!<br /> You are <?php echo $_POST["age"]; ?> years old. </body> </html>

  9. A First Server Round Trip Using Forms (4)

  10. GET and POST (Introduction) • There are two basic ways to send data back to a Web server • We call these HTTP verbs • In all there are about 30 verbs • http://annevankesteren.nl/2007/10/http-methods • Both GET and POST send data to Web servers

  11. HTTP GET • GET sends is data through the URL itself as a query string • The URL looks something like this • http://localhost/PhpProjectDemo1/welcome.php?fname=zaphod&age=42 • <input> values appear after the ? • Data appears as key=value pairs • A & separates each key=value pair • You don’t write the URL – HTTP does!

  12. HTTP POST • The request data does not appear inside the query string • Data is sent in the HTTP header itself • It’s possible to pull this data out of the header

  13. HTTP GET and POST (Comparison) • GET • Query strings are small (100 characters) • Posted data is visible • It’s possible to bookmark the page • PUT • Large data blocks can be posted • Posted data is hidden • Page cannot be bookmarked

  14. Reading Posted Data • $_GET and $_POST retrieve data send to the server via a GET or POST, respectively • They are built-in functions • Pass the ID of the input control as an argument

  15. Example <html> <body> Welcome <?php echo $_GET["fname"]; ?>!<br /> You are <?php echo $_GET["age"]; ?> years old. </body> </html>

  16. PHP Variables • Like JavaScript, variables are ‘loosely typed’ • Variables can be declared anywhere in a PHP script • Variable names • Must begin with a letter or underscore ‘_’ character • The following characters can be letters, numbers or the underscore • Variables cannot contain spaces

  17. PHP Variables (Declaring) • Variable declarations begin with the dollar sign ‘$’, followed by the variable name • An equals sign and value follow the declaration • Examples: $userName = “joe”; $pi = 3.14;

  18. Using Numeric Variables (1) • Arithmetic operations work similarly in PHP and JavaScript • Use the $ to reference all variable names $x = 10; $y = 100; print $x + $y; /* 110 */

  19. Using Numeric Variables (2) • The following prints 10 + 100 because the value is quoted $x = 10; $y = 100; print "$x + $y";

  20. PHP Strings (Introduction) • Strings work in PHP the same way they work in other languages • There are several string functions: • http://w3schools.com/php/php_ref_string.asp • The dot (.) is the concatenation operator

  21. PHP Functions (Introduction) • PHP has built-in functions just like any language • In all, there are about 700 so we will not get to all of them • Refer to http://w3schools.com/php/default.asp for a categorized list

  22. PHP Functions (Syntax) • It all looks just about like JavaScript (except the $ notation for variables) • Functions and accept 0, 1 or many arguments • Functions and return a value • Again, the arguments are loosely typed

  23. Declaring a PHP Function (Example) • Declare a function named ShowFooter <?php function ShowFooter() { print("<br />"); print(“Rendered " . date("y-m-d")); print("<br />"); } ?>

  24. Calling a Function (Example) • Call the ShowFooter function shown previously <?phpShowFooter(); ?>

More Related