PHP (Hypertext Preprocessor)

  • Just like other script language, using variables, loop, etc.
  • It runs on the server side and is embedded directly into HTML. Used to create dynamic, interactive websites.
  • PHP powers many popular platforms like WordPress and Laravel.
  • All php scripts start with <?php and with ?>
  • PHP can be placed directly inside HTML

PHP script - Example

<?php
$author = "John Smiths";
$message = "How are you?";
echo $author . " says " . $message;
?>

PHP - Forms

  • <form method="post" action="process.php" >
    • Method specifies how the data will be sent
    • Action specifies the file to send to. E.g. process.php
  • Post method sends all contents of a form with basically hidden headers (not easily visible to users)
  • Get method sends all form input in the URL requested using name=value pairs separated by ampersands (&)
    • E.g. process.php?name=John&number=345
    • Is visible in the URL shown in the browser
  • All form values are placed into an array
  • Assume a form contains one textbox called “lastname” and the form is submitted using the post method, invoking process.php
  • process.php could access the form data using:
    • $_POST[‘lastname’] or
    • Use extract($_POST) to imports form fields as variables
  • If the form used the get method, the form data would be available as:
    • $_GET[‘lastname’]

PHP Session handling