Performance Discussion

[Bobbo]

Hi,

A colleague and I were having a weasely discussion about
which of the following methods is quicker...
Method 1:

var = False
If <cond> Then var = True

Method 2:

If <cond> Then
var = True
Else
var = False
End If
The first is more concise, yet the second is clearer.

Does anyone have anything to contribute to our debate, to
save us taking it outside?!? ;-)

[Bob Barrows]

You're right: "weasely" is a good term. I doubt a user will ever detect the
difference between these two methods. In a looping situation, I might use
the first method. In any other situation, it will not matter. Use whichever
suits your style.

YMMV,
Bob Barrows

Bobbo wrote:

Hi,

A colleague and I were having a weasely discussion about
which of the following methods is quicker...
Method 1:

var = False
If <cond> Then var = True

Method 2:

If <cond> Then
var = True
Else
var = False
End If
The first is more concise, yet the second is clearer.

Does anyone have anything to contribute to our debate, to
save us taking it outside?!? ;-)

[Ray at]

How about:

var = <cond>

:P

Ray at work

"Bobbo" <ro************@yahoonospam.com> wrote in message
news:09****************************@phx.gbl...

Hi,

A colleague and I were having a weasely discussion about
which of the following methods is quicker...
Method 1:

var = False
If <cond> Then var = True

Method 2:

If <cond> Then
var = True
Else
var = False
End If
The first is more concise, yet the second is clearer.

Does anyone have anything to contribute to our debate, to
save us taking it outside?!? ;-)

[Bobbo]

For those interested, in a 100 million iteration loop,
Method 1 was the quickest (at approx 90% the time of
Method 2).

Incidentally, VB's IIF function was 10 times *slower* than
either of these two!

Right, I've finished being weasely now!

B.

[Chris Hohmann]

"Bobbo" <ro************@yahoonospam.com> wrote in message
news:0a****************************@phx.gbl...

For those interested, in a 100 million iteration loop,
Method 1 was the quickest (at approx 90% the time of
Method 2).

Incidentally, VB's IIF function was 10 times *slower* than
either of these two!

Right, I've finished being weasely now!

B.

Here are my findings:

Method 1: If
Method 2: If..Else
Method 3:Let

True
Method 1: 1.371094
Method 2: 0.9726563
Method 3: 0.7382813

False
Method 1: 0.9101563
Method 2: 0.921875
Method 3: 0.7304688

Mod
Method 1: 2.003906
Method 2: 1.792969
Method 3: 1.191406

I tested three case. Condition false, condition true and condition =
iterator mod 2. The mod 2 condition is important since it covers the
boolean space. In all three cases, Ray's let method was the best
performer. When the condition was true or mod 2, method 2 (if..else)
beat out method 1 (if). Only when the condition was false did method 1
beat out method 2 and then only by a small margin. So if I had to rank
them it would be method 3 (let), method 2 (if..else), method 1 (if).

HTH
-Chris

[Ray at]

I don't really think this is what he was looking for though, hence the ":P"
thing. Like, he was probably just using t/f as an example. My guess is
that he was wondering between something more like:
var = "Joe Jones"
If <cond> var = "Mary Jones"

vs.

If <cond> Then
var = "Mary Jones"
Else
var = "Joe Jones"
End If

In that case, I'd probably bet a dollar on the top method.

Ray at work

"Dave Anderson" <GT**********@spammotel.com> wrote in message
news:ua**************@TK2MSFTNGP11.phx.gbl...

"Ray at <%=sLocation%>" wrote:

How about:

var = <cond>
Amen.

--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per message.

Use of this email address implies consent to these terms. Please do not contact me directly or ask me to contact you directly for assistance. If your
question is worth asking, it's worth posting.

[Mark Schupp]

Actually the 1st structure would be doing 2 string assignments if the
condition is true where the 2nd structure always does a single string
assignment and should be faster overall. That said, I often use the 1st
structure to reduce the nesting level of complex if statements.

---1.a---
var = "Joe Jones"
If False Then var = "Mary Jones"
1,000,000 tries =>3023 ms

---2.a---
If False Then
var = "Mary Jones"
Else
var = "Joe Jones"
End If
1,000,000 tries =>3004 ms

---1.b---
var = "Joe Jones"
If True Then var = "Mary Jones"
1,000,000 tries =>4547 ms

---2.b---
If True Then
var = "Mary Jones"
Else
var = "Joe Jones"
End If
1,000,000 tries =>3145 ms
--
Mark Schupp
--
Head of Development
Integrity eLearning
Online Learning Solutions Provider
ms*****@ielearning.com
http://www.ielearning.com
714.637.9480 x17
"Ray at <%=sLocation%>" <as*@me.forit> wrote in message
news:eX**************@TK2MSFTNGP11.phx.gbl...

I don't really think this is what he was looking for though, hence the ":P" thing. Like, he was probably just using t/f as an example. My guess is
that he was wondering between something more like:
var = "Joe Jones"
If <cond> var = "Mary Jones"

vs.

If <cond> Then
var = "Mary Jones"
Else
var = "Joe Jones"
End If

In that case, I'd probably bet a dollar on the top method.

Ray at work

"Dave Anderson" <GT**********@spammotel.com> wrote in message
news:ua**************@TK2MSFTNGP11.phx.gbl...

"Ray at <%=sLocation%>" wrote:

How about:

var = <cond>

Amen.

--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per message.

Use

of this email address implies consent to these terms. Please do not

contact

me directly or ask me to contact you directly for assistance. If your
question is worth asking, it's worth posting.

[Ray at]

You are correct!

I ran through each method 10 million times, and got these results:

Method 1:
59 seconds

Method 2:
42 seconds

"Mark Schupp" <ms*****@ielearning.com> wrote in message
news:uD**************@TK2MSFTNGP12.phx.gbl...

Actually the 1st structure would be doing 2 string assignments if the
condition is true where the 2nd structure always does a single string
assignment and should be faster overall. That said, I often use the 1st
structure to reduce the nesting level of complex if statements.

---1.a---
var = "Joe Jones"
If False Then var = "Mary Jones"
1,000,000 tries =>3023 ms

---2.a---
If False Then
var = "Mary Jones"
Else
var = "Joe Jones"
End If
1,000,000 tries =>3004 ms

---1.b---
var = "Joe Jones"
If True Then var = "Mary Jones"
1,000,000 tries =>4547 ms

---2.b---
If True Then
var = "Mary Jones"
Else
var = "Joe Jones"
End If
1,000,000 tries =>3145 ms
--
Mark Schupp
--
Head of Development
Integrity eLearning
Online Learning Solutions Provider
ms*****@ielearning.com
http://www.ielearning.com
714.637.9480 x17
"Ray at <%=sLocation%>" <as*@me.forit> wrote in message
news:eX**************@TK2MSFTNGP11.phx.gbl...

I don't really think this is what he was looking for though, hence the

":P"

thing. Like, he was probably just using t/f as an example. My guess is
that he was wondering between something more like:
var = "Joe Jones"
If <cond> var = "Mary Jones"

vs.

If <cond> Then
var = "Mary Jones"
Else
var = "Joe Jones"
End If

In that case, I'd probably bet a dollar on the top method.

Ray at work

"Dave Anderson" <GT**********@spammotel.com> wrote in message
news:ua**************@TK2MSFTNGP11.phx.gbl...

"Ray at <%=sLocation%>" wrote:
>
> How about:
>
> var = <cond>

Amen.

--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per

message. Use

of this email address implies consent to these terms. Please do not

contact

me directly or ask me to contact you directly for assistance. If your
question is worth asking, it's worth posting.