jQuery: check if a checkbox is checked

HTML

<table class="table" id="tagstable">
   <tbody>
    
   </tbody>
</table>

<button type="button" class="btn btn-success addTagbtn">Add new tag</button>

JavaScript

var myarray = ["A", "B", "C", "D", "E", "F", "G", "H"];
 var counter = 0;
$(document).ready(function()
{
        var html = ''
        for (var i = 0; i < myarray.length; i++)
        {
                html += '<td><label class="mt-checkbox mt-checkbox-outline"><input type="checkbox" class="chkclass">' + myarray[i] + '<span></span></label></td>';
                if ((i + 1) % 4 == 0) html += '</tr><tr>';
        }
        $("#tagstable tbody").append('<tr>' + html + '</tr>');
});
$(document).on("click", ".addTagbtn", function(event)
{
        appendToTagstable();
});

function appendToTagstable()
{
        var taghtml = '';
       	counter ++ ;
        taghtml = '<td><label class="mt-checkbox mt-checkbox-outline"><input type="checkbox">I<span></span></label></td>';
         $("#tagstable tbody").append(taghtml);
        if(counter% 4 == 0) {
        	$("#tagstable tbody").append("</tr><tr>");
        }
       
        return false;
}