how to get className value using id in jquery

Question

I want class name value using id but input type is file.

<input type='file' id="imgInp"  file="file" class="@userSurvey.Id"/>

 jquery Code

$('input[type="file"]').change(function(e){
    var fileName = e.target.files[0].name;
    $.each($('#imgInp')[i].files, function (i, file) {

        fileData.append('file-' + i, e.target.files[i]);

        });

    alert('The file "' + fileName +  '" has been selected.');
});

 how to get classname value