string
is an alias in C# for System.String
. So technically, there is no difference. It’s like int
vs. System.Int32
.
As far as guidelines, it’s generally recommended to use string
any time you’re referring to an object.
string place = "world";
Likewise, it’s generally recommended to use String
if you need to refer specifically to the class.
string greet = String.Format("Hello {0}!", place);