Php echo returning two additional unknown characters

Question

I'm trying to perform an Ajax POST request and the result is returned from PHP by echo . I've just noticed that the result is returning two additional unknown characters.

This is my JavaScript:

$.ajax({
            type: "POST",
            url: "php/login.php",
            data: loginDataString,
            cache: false,
            success: function(result){
                alert(result);
                swal("Incorrect", result, "error");
            }
        });

And my whole PHP

<?php
$con = mysqli_connect("localhost","root","","EugeneStore");
if(!$con){
    die("Connection error: " . mysqli_error());
}
if($_SERVER['REQUEST_METHOD']=='POST'){
        $UN = $_POST['login_username'];
        $PW = $_POST['login_password'];
        date_default_timezone_set('Asia/Manila');
        $t=time(); $timeDAY = date('d',$t); $timeMONTH = date('m',$t); $timeYEAR = date('Y',$t); $timeYEAR2 = date('y',$t); $CURRENTDATE = "$timeDAY/$timeMONTH/$timeYEAR"; $a2 = date('H',$t); $a3 = date('i',$t); $ampm = "";
                    if ($a2 >= 0 && $a2 <= 11){
                        $ampm = "AM";
                    }
                    if ($a2 >= 12 && $a2 <= 23){
                        $ampm = "PM";
                    }
                    if ($a2 == 13){
                        $a2 = 1;
                    }
                    if ($a2 == 14){
                        $a2 = 2;
                    }
                    if ($a2 == 15){
                        $a2 = 3;
                    }
                    if ($a2 == 16){
                        $a2 = 4;
                    }
                    if ($a2 == 17){
                        $a2 = 5;
                    }
                    if ($a2 == 18){
                        $a2 = 6;
                    }
                    if ($a2 == 19){
                        $a2 = 7;
                    }
                    if ($a2 == 20){
                        $a2 = 8;
                    }
                    if ($a2 == 21){
                        $a2 = 9;
                    }
                    if ($a2 == 22){
                        $a2 = 10;
                    }
                    if ($a2 == 23){
                        $a2 = 11;
                    }

        $CURRENTTIME = "$a2:$a3 $ampm";

        $sql = "SELECT * FROM Users WHERE Username='".$UN."' AND Password='".$PW."'";
        $result = mysqli_query($con,$sql);
        $count = mysqli_num_rows($result);
        if($count==1) {
            $rows00 = mysqli_fetch_array($result);
            if($rows00['UserType'] == "Admin") {
                $ADDSYSREC = mysqli_query($con, "INSERT INTO SystemLogs(Username, Date, Time, Information, Type) 
                VALUES('".$rows00['Username']."', '".$CURRENTDATE."', '".$CURRENTTIME."', '".$rows00['Username']." Logged into the system', 'Admin')");
                echo "Login Correct Admin";

            }
            if($rows00['UserType'] == "Member") {
                $ADDSYSREC = mysqli_query($con, "INSERT INTO SystemLogs(Username, Date, Time, Information, Type) 
                VALUES('".$rows00['Username']."', '".$CURRENTDATE."', '".$CURRENTTIME."', '".$rows00['Username']." Logged into the system', 'Member')");
                echo "Login Correct Member";

            }
        } else {    
            echo 'Wrong username or password';
        }
} else {
    echo "Something is wrong with the system. Try again Later";
}   
?>

And the result here

Answer 1

Whenever you have a PHP-only file, you should leave out the closing ?> tag. This question has a number of explanations why, but the big reason is to ensure that no whitespace or hidden characters will be output by the web server.