I want to add highlight class on selected row in ajax table while clicking edit button. I don’t know why my code is not working. Could you help me? Thanks in advance.

function getData(){
            $.ajax({
                url:"<?php echo base_url(); ?>copycontrol/getData",
                method:"post",
                dataType: "json",
                success:function(data){
                    var html='';
                    var i;
                    var count= 1;
                    html+='<table id="copyTable" class="table table-bordered"><tr><th class="border_none"style="width:2%"></th><th  class="border_none" style="width:86%">Procedure Description</th><th class="text-center" style="width:12%">Operations</th></tr>';
                    for(i in data){
                        html+='<tr><td>'+count+'</td><td onclick="copy(this)">'+data[i].name+'</td><td><button type="button" class="delete" id='+data[i].id+'><i class="fa fa-trash" title="Delete" style="font-size:20px;"></i></button><button type="button" class="edit" title="Edit" id='+data[i].id+'><i class="fa fa-edit" style="font-size:20px;"></i></button></td></tr>';
                        count++;
                    }
                    html+='</table>';
                    $('#showData').html(html);
                }
            });
        }

$(document).on('click', '.edit', function(){
            var eID = $(this).attr("id");
            $('#copy_info').text("Edit row.");
            $.ajax({
                url:"<?php echo base_url(); ?>copycontrol/fetchSingleData",
                method:"post",
                data:{eID: eID},
                dataType:"json",
                success:function(data){
                    
                    var i;
                    for(i in data){
                        $('#name').val(data[i].name);
                    }
                    $('#single').val(eID);
                    $('#submit').text("Edit");
                    $('#submit').val("update");
                    $('#name').focus();

                    var selectedRow = $(this).closest('tr').find("td:eq(0)").text();
                    $("tr:nth-child(" + selectedRow + ") ").addClass('highlight');

                    if($('#submit').val() == "submit")
                    {
                        $('#success').text("Row data was successfuly edited.");
                        $('#success').fadeOut(3000);
                        
                    }
                }
            });
        });

This code produces error: “Uncaught Error: Syntax error, unrecognized expression: :nth-child()…”

var selectedRow = $(this).closest('tr').find("td:eq(0)").text();
$("tr:nth-child(" + selectedRow + ") ").addClass('highlight');