Why am i always getting null?

Question

var selectedID= $('#@Html.IdFor(m => m.StudentId)').val();

 Note: This value is a dropdownlist is read from a dropdownlist when the page loads.

 

 why is this always giving me the result of  "  " when im using it in my view (mvc)??

but when i write it in console im actually getting the value of the Id.

 

Can someone please help me out?

Thank you in advance.