Wow, thats pretty yuck, you would think on the face of it that it would be quicker. But oh well. Back to using A = ''; which I had thought would have been slowest.
An interesting thing to have learnt for the week. Nahum. > [EMAIL PROTECTED] <mailto:owner-delphi@;delphi.org.nz> > wrote on > > 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/ --------------------------------------------------------------------------- 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/
