Null vs Empty

Hello Experts,

Please take a look -

1. string str = null;

AND

2. string str = "";(Empty)

Now can anyone tell me which str string will take higher size and what is difference between null and empty?

Thanx in advance.

From MSDN:

Null Strings and Empty Strings

An empty string is an instance of a System.String object that contains zero characters. Empty strings are used quite commonly in various programming scenarios to represent a blank text field. You can call methods on empty strings because they are validSystem.String objects. Empty strings are initialized like this:

string s = "";

By contrast, a null string does not refer to an instance of a System.String object and any attempt to call a method on a null string results in a NullReferenceException. However, you can use null strings in concatenation and comparison operations with other strings. The following examples illustrate some cases in which a reference to a null string does and does not cause an exception to be thrown:

string str = "hello";
string nullStr = null;
string emptyStr = "";

string tempStr  = str + nullStr; // tempStr = "hello"
bool b = (emptyStr == nullStr);// b = false;
emptyStr + nullStr = ""; // creates a new empty string
int I  = nullStr.Length; // throws NullReferenceException

Hi,

You may also try to give this short discussion a read: http://codeasp.net/forums/asp-net-topics/getting-started-general-asp-net/117/what-is-difference-between-null-vs-string-empty-vsin-c