Syntax
$query = $_GET["q"] ?? "";
$clean = trim($query);Examples
Reading an optional query value
A small, runnable example of this syntax.
<?php
$query = $_GET["q"] ?? "";
$query = trim($query);
if ($query !== "") {
echo htmlspecialchars($query, ENT_QUOTES, "UTF-8");
}
?>Best practices
- Validate input for its expected shape and escape output for its destination; never treat request data as safe by default.
- Keep examples small while learning, then combine the idea with a real project.
At a glance
- Purpose
- Server-side web applications
- File extension
- .php
- Runs in
- PHP runtime on a server or CLI
- Usually used with
- HTML, databases and web servers