String vs string [duplicate]

Answer 1

There is not a difference. string is an alias that the compiler converts to System.String.

In fact, it's even aliased in MSIL:

.method private hidebysig static void  Main(string[] args) cil managed

Answer 2

just a bit note: string/String is not the only couple of aliases: eg. Integer,Int32, int are all aliases.

@mliesen: it doesn't happend in C#, it's not like C. this because from C# you don't create executable but a per-compiled code, as java.

Answer 3

The lower case version is just an alias to the actual class String. There is no real difference as far as IL generated.

Answer 4

Considering that an “int” is different in some languages depending on 16bit/32bit system, a "string" could in the future evolve to not be the same as System.String.

But for now it is.

Answer 5

There is no difference. string is a C# language keyword which refers to the class System.String, just like int is a keyword which refers to System.Int32.

Answer 6

They are aliases and are interchangeable. However, stylistically, for declarations, I use the lowercased string, and for the static methods, I use String.

string foo = "bar";

if( foo != String.Empty )
{
   Console.WriteLine(String.Format("foo.Length = {0}", foo.Length));
}