Isnullorempty and S = NULL | S. Length = 0 which is fast?

This section describes how to compare a method of string with an attribute when determining whether a string variable is null. To give a string variable 's', which of the following expressions is faster?

1. String. isnullorempty (s)

2. S = NULL | S. Length = 0

If you guess the second one, you are right. It will be 15% faster than the string. isnullorempty method, but this is measured in one second per million!

Here is a simple example to compare two methods:

Using system;

 

Namespace stringnullempty

{

Class Program

{

Static void main (string [] ARGs)

{

Long Loop = 100000000;

String S = NULL;

Long option = 0;

Long empties1 = 0;

Long empties2 = 0;

 

Datetime time1 = datetime. now;

 

For (long I = 0; I <loop; I ++)

{

Option = I % 4;

Switch (option)

{

Case 0:

S = NULL;

Break;

Case 1:

S = string. empty;

Break;

Case 2:

S = "H ";

Break;

Case 3:

S = "hi ";

Break;

}

If (string. isnullorempty (s ))

Empties1 ++;

}

 

Datetime time2 = datetime. now;

 

For (long I = 0; I <loop; I ++)

{

Option = I % 4;

Switch (option)

{

Case 0:

S = NULL;

Break;

Case 1:

S = string. empty;

Break;

Case 2:

S = "H ";

Break;

Case 3:

S = "hi ";

Break;

}

If (S = NULL | S. Length = 0)

Empties2 ++;

}

 

Datetime time3 = datetime. now;

 

Timespan span1 = time2.subtract (time1 );

Timespan span2 = time3.subtract (time2 );

Console. writeline ("(string. isnullorempty (s): Time = {0} empties = {1 }",

Span1, empties1 );

Console. writeline ("(S = NULL | S. Length = 0): Time = {0} empties = {1 }",

Span2, empties2 );

Console. Readline ();

}

}

}

The result is as follows:

(String. isnullorempty (s): Time = 00:00:06. 8437500 empties = 50000000

(S = NULL | S. Length = 0): Time = 00:00:05. 9218750 empties = 50000000

Bytes ---------------------------------------------------------------------------------------------

It can be seen that although string. isnullorempty runs slowly, it is easy to read and Microsoft's design is quite user-friendly ~