如何检查mysqli_escape_string是否正常工作？

Question

这是我的代码

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);

$name = mysqli_real_escape_string($conn, $_POST["name"]);
$address = mysqli_real_escape_string($conn, $_POST["address"]); 
$city = mysqli_real_escape_string($conn, $_POST["city"]);
$state = mysqli_real_escape_string($conn, $_POST["state"]);
$zipcode = mysqli_real_escape_string($conn, $_POST["zipcode"]); 
$country = mysqli_real_escape_string($conn, $_POST["country"]);
$month = mysqli_real_escape_string($conn, $_POST["month"]);
$day = mysqli_real_escape_string($conn, $_POST["day"]);

我如何知道它是否正常工作？