Arrays, Strings, Superglobals, and Form Data Processing
Work with the data structures and request inputs that appear constantly in real PHP applications.
Inside this chapter
- Indexed and Associative Arrays
- String Handling
- Superglobals
- Simple Form Processing
- Business Example
Series navigation
Study the chapters in order for the clearest path from PHP basics to backend architecture, security, deployment, and production engineering habits. Use the navigation at the bottom to move smoothly through the full tutorial series.
Indexed and Associative Arrays
$skills = array("PHP", "MySQL", "JavaScript");
$user = array(
"name" => "Rina",
"role" => "Admin"
);Arrays are one of the most important PHP structures. They are used for collections, mappings, configuration sets, query results, request payloads, and more.
String Handling
$fullName = $firstName . " " . $lastName;
$length = strlen($fullName);PHP applications often process user input, URLs, query strings, filenames, and formatted messages. Strong string handling is therefore essential.
Superglobals
$_GETfor query-string parameters$_POSTfor submitted form data$_SERVERfor request and server metadata$_FILESfor uploaded files$_SESSIONfor server-side session data$_COOKIEfor browser cookie values
Simple Form Processing
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
$email = $_POST['email'] ?? '';
echo "Received: " . htmlspecialchars($email);
}This pattern is central to login forms, registration pages, contact forms, search pages, and admin updates.
Business Example
A student portal might accept search filters through $_GET, registration fields through $_POST, and file uploads through $_FILES. These request structures shape most everyday PHP application behavior.