Replace your code with this .
<?php
try{
$db = mysqli_connect ('localhost', 'root', '', 'car_rental') or die ("SQL is Off");
}
catch (Exception $e){
echo "SQL is Off";
exit;
}
echo "success";
$email = $_POST["email"];
$pass = $_POST["pass"];
mysqli_select_db($db,"car_rental");
$result = mysqli_query($db,"SELECT email, users FROM users WHERE email =$email");
//$row = mysql_fetch_array($result);
$row = $result->fetch_array(MYSQLI_ASSOC);
if($row["email"]==$email && $row["pass"]==$pass)
echo"You are a validated user.";
else
echo"Sorry, your credentials are not valid, Please try again.";
?>
4
solved mysql_select_db() expects parameter 2 to be resource, object given PHP validation