How can you ensure that user-provided data is properly sanitized and validated before displaying it in a text field in PHP?

To ensure user-provided data is properly sanitized and validated before displaying it in a text field in PHP, you can use functions like htmlspecialchars() to sanitize the data and regular expressions or built-in PHP functions to validate it. By sanitizing the data, you can prevent cross-site scripting attacks, and by validating it, you can ensure that only the expected format or type of data is displayed in the text field.

// Sanitize and validate user input before displaying in a text field
$user_input = $_POST['user_input']; // Assuming user input is coming from a form submission

// Sanitize user input
$sanitized_input = htmlspecialchars($user_input);

// Validate user input (e.g. check if it is a valid email address)
if (filter_var($sanitized_input, FILTER_VALIDATE_EMAIL)) {
    echo '<input type="text" value="' . $sanitized_input . '">';
} else {
    echo 'Invalid email address';
}