How To Store All Array Value in One Variable As String in C#

ArrayList list = new ArrayList();
list.Add("One");
list.Add("Two");
list.Add("Three");
list.Add(5);
foreach (var item in list)
{
if(StrList != "")
{
StrList = StrList + "," + item.ToString();
}
else
{
StrList = item.ToString();
}

}

List objOrder = new List();