Thread: String.empty v.s. string.null

Code:

String s;

s = null;    // string is NULL. 

s = "";     // string is empty.

There seems to be a IsEmptyOrNull() function for String in managed code, perhaps that's what you want?

--
Mats

Well, I m only a C programmer, but looking at http://msdn.microsoft.com/en-us/libr...ing.empty.aspx
it says that String.Empty is the same as "" (a blank string)

So String.Empty is just the "" string and nothing more. null is...null

Now, I suppose you cannot use null with String.Compare() or similar functions.

EDIT: mastp was too fast
EDIT2: Now I am curious. What is the REAL difference between NULL and "". If you assign null on a string it will have the null value. If you assign "" it will have what? A different value than null to indicate the differense?

It's easier to imagine if you see the variables as pointers (or references as the .NET term is). A null string is simply the pointer having a null value, the value 0. It doesn't point anywhere.

Code:

string Name = null;

Name = 0x00000000

An empty string is actually a string in memory of 0-length (with or without a null terminator im not sure). The pointer has a value, an adress to where the string is.

Code:

string Name = "";

Name = 0x12345678
 |
 v

+----+
| \0 |
+----+

And a normal string is similar to an empty string, only there actually are some characters in memory.

Code:

string Name = "Hi";

Name = 0x12345678
 |
 v

+---+---+----+
| H | i | \0 |
+---+---+----+