That will be about 3 times or more slower than length(a) - given that A is a string.
Delphi's handling of single characters in a string is rather horrible. It generally creates a temporary long string of 1 character copies from the original string and then does the compare - Yuck!! Plus of course you have just added a compiler generated try - finally around you block of code. Myles. -----Original Message----- From: Nahum Wild [mailto:Nahum.wild@;payglobal.com] Sent: Thursday, 31 October 2002 4:36 p.m. To: Multiple recipients of list delphi Subject: RE: [DUG]: Empty string test How about A[0] = 0; ? > [EMAIL PROTECTED] <mailto:owner-delphi@;delphi.org.nz> > wrote on > > Nope, That is the most efficient form ie (A = ''). The compiler does > a nice job of optimising it - basically a single instruction - > ignoring the jmp > > eg > cmp dword ptr [es],$00 > jnz ... > > Compare this to Length(A) > > Move eax, ecx > Call @LStrLen > test eax,eax > jnz ... > > And LStrLen is > tst eax,eax > jz $03 > mov eax,[eax-4] > ret > > Myles. > > > > > > -----Original Message----- > From: vss [mailto:vss@;vss.co.nz] > Sent: Thursday, 31 October 2002 4:04 p.m. > To: Multiple recipients of list delphi > Subject: Re: [DUG]: Empty string test > > > I second that. if legnth(mystring)=0 then showmessage('its empty') > > Jeremy > > -----Original Message----- > From: "Jeremy North" <[EMAIL PROTECTED]> > To: Multiple recipients of list delphi <[EMAIL PROTECTED]> > Date: Thu, 31 Oct 2002 14:00:41 +1100 > Subject: Re: [DUG]: Empty string test > >> >> I was once told that checking the length was. >> The person that told me said that it was recommend by boundschecker >> application. JED >> >>> Whats the fastest way to test for an empty string >>> I just get the feeling that String = '' is not good practice >> >> >> >> This email and any files transmitted with it are confidential and >> intended solely for the use of the individual or entity to whom they >> are addressed. If you have received this email in error please >> notify the [EMAIL PROTECTED] >> >> > -------------------------------------------------------------- > --------- >> ---- >> New Zealand Delphi Users group - Delphi List - >> [EMAIL PROTECTED] Website: >> http://www.delphi.org.nz To UnSub, send email to: >> [EMAIL PROTECTED] with body of "unsubscribe delphi" >> Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ > > -------------------------------------------------------------- > ------------- > New Zealand Delphi Users group - Delphi List - > [EMAIL PROTECTED] > Website: http://www.delphi.org.nz > To UnSub, send email to: [EMAIL PROTECTED] > with body of "unsubscribe delphi" > Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ > -------------------------------------------------------------- > ------------- > New Zealand Delphi Users group - Delphi List - > [EMAIL PROTECTED] > Website: http://www.delphi.org.nz > To UnSub, send email to: [EMAIL PROTECTED] > with body of "unsubscribe delphi" > Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ --------------------------------------------------------------------------- New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] Website: http://www.delphi.org.nz To UnSub, send email to: [EMAIL PROTECTED] with body of "unsubscribe delphi" Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ --------------------------------------------------------------------------- New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] Website: http://www.delphi.org.nz To UnSub, send email to: [EMAIL PROTECTED] with body of "unsubscribe delphi" Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/
