Handling GET and POST

HTML forms and links send data via HTTP methods. PHP exposes query strings in $_GET and form bodies in $_POST.

GET — read, idempotent, bookmarkable

<a href="/search.php?q=php&page=2">Page 2</a>

$q = trim($_GET['q'] ?? '');
$page = max(1, (int) ($_GET['page'] ?? 1));

POST — mutations, larger payloads

<form method="post" action="/subscribe.php">
  <input name="email" type="email">
</form>

$email = filter_input(INPUT_POST, 'email', FILTER_VALIDATE_EMAIL);

Method selection

Use GET for safe reads (search, filters). Use POST for creates/updates/deletes. REST APIs also use PUT/PATCH/DELETE—often via frameworks or $_SERVER['REQUEST_METHOD'].

Playground note

Assign sample arrays to simulate input—the validation logic is what you practice here.

Important interview questions and answers

1. Q: Why not put passwords in GET?
   A: Query strings appear in logs, history, and Referer headers—use POST over HTTPS.
2. Q: filter_input vs raw $_POST?
   A: filter_input applies validation/sanitization filters in one step.

Self-check

1. Which superglobal holds ?page=2?
2. Why validate email with FILTER_VALIDATE_EMAIL?