Every once in a while, someone will post a snippet with code such as...
if ( somestring == "" )
... and in many cases someone else will respond, "Always use
if ( somestring.Length == 0 ), it's more efficient."
... or maybe someone will respond, "Always use
if ( somestring == System.String.Empty ), it's more efficient."
And neither will back up his claim.
Here are some numbers; performing each test against a provided
UInt32.MaxValue times) yields:
00:01:09.3764731 // if ( providedstring == "" )
00:01:10.3869118 // if ( providedstring == localstaticemptystring )
00:01:10.1249723 // if ( providedstring == System.String.Empty )
00:00:38.1334581 // if ( providedstring.Length == 0 )
00:01:36.3041617 // if ( providedstring == "" )
00:01:36.6285272 // if ( providedstring == localstaticemptystring )
00:01:35.9541459 // if ( providedstring == System.String.Empty )
00:00:31.6860051 // if ( providedstring.Length == 0 )
The difference between comparing against a literal empty
string and a
string is negligible. And note that somehow when the provided
string isn't empty, those tests take even longer!
Length of the
string is the clear winner here, though it's not as Earth-shattering as some might have you believe.
- 2008-02-21 First submitted
BSCS 1992 Wentworth Institute of Technology
Originally from the Boston (MA) area. Lived in SoCal for a while. Now in the Phoenix (AZ) area.
OpenVMS enthusiast, ISO 8601 evangelist, photographer, opinionated SOB
"If you need help knowing what to think, let me know and I'll tell you." -- Jeffrey Snover [MSFT]
"Typing is no substitute for thinking." -- R.W. Hamming
"I find it appalling that you can become a programmer with less training than it takes to become a plumber." -- Bjarne Stroustrup
ZagNut’s Law: Arrogance is inversely proportional to ability.
"Well blow me sideways with a plastic marionette. I've just learned something new - and if I could award you a 100 for that post I would. Way to go you keyboard lovegod you." -- Pete O'Hanlon
"linq'ish" sounds like "inept" in German -- Andreas Gieriet
"Things would be different if I ran the zoo." -- Dr. Seuss
"Wrong is evil, and it must be defeated." – Jeff Ello
"A good designer must rely on experience, on precise, logical thinking, and on pedantic exactness." -- Nigel Shaw
“It’s always easier to do it the hard way.” -- Blackhart
“If Unix wasn’t so bad that you can’t give it away, Bill Gates would never have succeeded in selling Windows.” -- Blackhart
"Omit needless local variables." -- Strunk... had he taught programming
"We learn more from our mistakes than we do from getting it right the first time."
My first rule of debugging: "If you get a different error message, you're making progress."
My golden rule of database management: "Do not unto others' databases as you would not have done unto yours."
My general rule of software development: "Design should be top-down, but implementation should be bottom-up."