I have several reasons for not using evaluate:
1. I think it is *very* ugly.
2. I think that if you're using Evaluate() then you're probably not doing
something right, or you haven't thought it through fully. There are a few
occasions where it is necessary, but not as often as it is used. (Tie-in
with number 1: I have seen some *naaaasty* code that used Evaluate() all
over the place. <shiver>)
3. It's is *much* slower than pretty much anything else.
Now, I know how much we hard-core geeks love metrics, so I'm going to
provide some for that last statement. I ran time trials of assigments using
Evaluate() and the equivalent statements without it. Results and the code
to generate them are below (remember that lower is faster and better):
Struct: 0,78,422,797,4000
Eval: 16,203,1063,2078,10422
Struct: 0,78,391,796,3984
Eval: 31,219,1046,2110,10438
Struct: 16,78,391,782,3984
Eval: 15,203,1016,2078,10375
Struct: 0,79,390,781,4015
Eval: 16,203,1031,2078,10532
Struct: 16,78,407,797,4000
Eval: 15,203,1046,2078,10453
The code:
<CFSETTING ENABLECFOUTPUTONLY="Yes">
<!---
test.cfm
--->
<CFLOOP FROM="1" TO="5" INDEX="j">
<CFSET StructTimes="">
<CFSET EvalTimes="">
<CFLOOP LIST="100,1000,5000,10000,50000" INDEX="Iterations">
<CFSET Bag=StructNew()>
<!--- set up our pile o' dummy vars --->
<CFLOOP FROM="1" TO="#Iterations#" INDEX="i">
<CFSET Bag["a#i#"]=Iterations - i>
</CFLOOP>
<!--- now test with structure calls --->
<CFSET Start=GetTickCount()>
<CFLOOP FROM="1" TO="#Iterations#" INDEX="i">
<CFSET foo=Bag["a#i#"]>
</CFLOOP>
<CFSET End=GetTickCount()>
<CFSET StructTimes=ListAppend(StructTimes,End-Start)>
<!--- now test with Evaluate() calls --->
<CFSET Start=GetTickCount()>
<CFLOOP FROM="1" TO="#Iterations#" INDEX="i">
<CFSET foo=Evaluate("Bag.a#i#")>
</CFLOOP>
<CFSET End=GetTickCount()>
<CFSET EvalTimes=ListAppend(EvalTimes,End-Start)>
</CFLOOP>
<CFOUTPUT><P>Struct: #StructTimes#<BR>Eval: #EvalTimes#</P></CFOUTPUT>
</CFLOOP>
<CFSETTING ENABLECFOUTPUTONLY="No">
-----Original Message-----
From: Jeremy Allen [mailto:[EMAIL PROTECTED]]
Sent: Thursday, August 31, 2000 1:24 PM
To: [EMAIL PROTECTED]
Subject: RE: getting data from queries as a structure/array
Why would you avoid using Evaluate I can think of
a few reasons but I am interested in hearing your
Reasons :)
Jeremy Allen
[EMAIL PROTECTED]
------------------------------------------------------------------------------
Archives: http://www.mail-archive.com/[email protected]/
To Unsubscribe visit
http://www.houseoffusion.com/index.cfm?sidebar=lists&body=lists/cf_talk or send a
message to [EMAIL PROTECTED] with 'unsubscribe' in the body.
