I could not find solution to this php error Parse error: syntax error, unexpected ' ' (T_STRING), expecting function (T_FUNCTION) or const (T_CONST)?

Question

This is my Code: ( ! ) Parse error: syntax error, unexpected ' ' (T_STRING), expecting function (T_FUNCTION) or const (T_CONST) in C:\wamp64\www\lab13\upload.php on line 13

<?php
$sname = $_POST['name'];
// $coursenumber = $_POST['cno'];
$cname = $_POST['cname'];
$sem = $_POST['semester'];
$year = $_POST['year'];


class Course {
    public $Student_name;       
    public $course_name;
    public $Semester;
    public $year;
public function __construct($Student_name, $course_name,$Semester,$year) 
{
    $this-> $Student_name = $Student_name;
    $this-> $course_name=$course_name;
    $this-> $Semester=$Semester;
    $this-> $year=$year;
}
public function display_course() {  
    echo "Student Name : " .$Student_name  . "</br>";
    echo "Course Name : " .$course_name  . "</br>";
    echo "Semester : " .$Semester  . "</br>";
    echo "Year : " .$year  . "</br>";
}
}
$course = new Course($sname, $cname,$sem,$year);
$course->display_course();
?>