Difference between string str=" "; and string str1=string Empty

URL:- http://myjourneytodotnet.blogspot.in/... Whenever we declare string str=""; then it will create a new object. But whenever we declare string str1=string.Empty then it will create no object which makes string.Empty more efficient. However, string.Empty is a read-only field whereas "" is a compile time Constant. So, string str1=string.Empty is the most prefered way of Writing the code. But string.Empty can't use inside Switch Case Statement because as it is a read-only so it will generate error.