jQuery checkbox always returns 'undefined' using foreach

I am trying to implement a code to get checkbox list attr('name') while return 'undefind' word. What is the reason for this and How this one remove?

 

  jQuery(document).on("change", "#chkdaypart", function () {
var daypartText;
$(this).each(function (e) {

if (this.checked) {

daypartText = daypartText + $(this).attr('name');

if (daypartText == "undefinedDaytime–Weekday(06:26:00-17:25:00)") {
$('#daysTD').html('')
$('#daysTD').html('

• All
• Monday
• Tuesday
• Wednesday
• Thursday
• Friday

')
}
else if (daypartText == "undefinedDaytime-Weekend(06:26:00-17:25:00)") {

$('#daysTD').html('');
$('#daysTD').html('

• All
• Sunday
• Saturday

');
}

}
else {
$('#daysTD').html('');
$('#daysTD').html('

• All
• Sunday
• Monday
• Tuesday
• Wednesday
• Thursday
• Friday
• Saturday

')

}
});
});

 

 

 

And 'chkdaypart' id contain list of checkboxlist which return list of names like this:-

 

• 
  All

@foreach (var items in ViewData["daypart"] as List)
{

• 
  
  @items.Text
  

}