What are common errors or pitfalls when working with $_POST in PHP forms?

One common error when working with $_POST in PHP forms is not checking if the form has been submitted before accessing the $_POST values. This can lead to undefined index errors if the form has not been submitted yet. To solve this, always check if the form has been submitted using isset() or !empty() before accessing $_POST values. 

if(isset($_POST['submit'])) {
    // Form has been submitted, safe to access $_POST values
    $username = $_POST['username'];
    $password = $_POST['password'];
    
    // Rest of your form processing code here
}

Keywords

$_POST PHP forms validation security data sanitization

Related Questions