PHP Form Handling

PHP Form Handling

Handling HTML forms is one of the most common tasks in PHP web development. Whenever a user submits a login form, a contact form, or a search query, PHP acts as the bridge between the user interface and the backend server.

The PHP superglobals $_GET and $_POST are used to collect form data.

A Simple HTML Form

Let's imagine you have a simple HTML form with two input fields (Name and Email) and a submit button.

<form action="welcome.php" method="post">
  Name: <input type="text" name="name"><br>
  E-mail: <input type="text" name="email"><br>
  <input type="submit">
</form>

When the user fills out this form and clicks the submit button, the form data is sent to a PHP file named welcome.php for processing. The data is sent using the HTTP POST method (because we specified method="post").

Collecting the Data with PHP

To display the submitted data inside welcome.php, you can use the $_POST superglobal array. The keys in the $_POST array match the name attributes of the HTML input fields.

<?php
// In a real scenario, this data is sent from the HTML form.
// We are simulating the submission here:
$_POST['name'] = "John Doe";
$_POST['email'] = "john@example.com";

echo "Welcome " . $_POST["name"] . "<br>";
echo "Your email address is: " . $_POST["email"];
?>

GET vs. POST: Which Should You Use?

Both GET and POST create an array of key/value pairs that hold the form data. However, they have completely different use cases:

• $_GET: Appends the form data directly to the URL (e.g., test.php?name=John&age=25). It is highly visible to everyone. Use GET for non-sensitive data, like search queries or filtering products on an e-commerce site, so users can bookmark the page.
• $_POST: Sends the data invisibly behind the scenes within the HTTP request body. It has no size limits and is much more secure. Use POST for passwords, personal information, and any action that updates a database.

Now that you know how to collect data, we must learn how to secure it. Let's move on to Form Validation!