How can filter_input be used to validate user input in PHP?

Using filter_input in PHP allows you to validate user input by filtering it based on a specified filter type. This function checks the input data against a specified filter and returns the filtered data if it passes the validation, or false if it fails. This can help prevent common security vulnerabilities such as SQL injection and cross-site scripting attacks. 

// Example of using filter_input to validate user input
$user_input = filter_input(INPUT_POST, 'user_input', FILTER_SANITIZE_STRING);

if($user_input){
    // Valid input, proceed with processing
    echo "User input is: " . $user_input;
} else {
    // Invalid input, handle the error
    echo "Invalid user input";
}

Keywords

filter_input validate user input PHP error types

Related Questions