Comments on: Find Matching Data in Array Speed Test

By: Slow inner loop many to many matching

Slow inner loop many to many matching — Fri, 12 Oct 2012 08:10:24 +0000

[...] [...]

By: Rick Rothstein (MVP - Excel)

Rick Rothstein (MVP - Excel) — Thu, 13 Sep 2012 16:06:15 +0000

@snb,

Thanks for running the test! I figured it would be slower than yours, but I thought it might have been a little closer than that though. Just out of curiosity, did you try running your code without using the Filter function? InStr is fast, so I wonder if Join’ing the entire array rather than Filter’ing the array and Join’ing what results might be faster.

Function IsInArray_snb(sn As Variant, c01 As String) As Boolean
IsInArray_snb = InStr(“_” & Join(sn, “_”) & “_”, “_” & c01 & “_”)
End Function

Note: I left out the Optional c02 argument since your original code, as well as this one, never make use of it.

By: snb

snb — Thu, 13 Sep 2012 13:50:28 +0000

@Rick

on my system it takes approx. 40 % more time than my method does, but it is faster than DK’s & JP’s method.

By: Rick Rothstein (MVP - Excel)

Rick Rothstein (MVP - Excel) — Thu, 13 Sep 2012 04:33:01 +0000

Just a guess, but this is probably not as fast as snb’s one-liner, but I thought I would put it out there in case someone wanted to test it…

Function IsInArray_Rick(vArr As Variant, S As String) As Boolean
IsInArray_Rick = UBound(Split(Chr$(1) & Join(vArr, Chr$(1)) & Chr$(1), Chr$(1) & S & Chr$(1), 2))
End Function

By: snb

snb — Wed, 12 Sep 2012 14:55:28 +0000

Highly improbable when using:

IsInArray_snb = InStr(Chr(0) & Join(Filter(sn, c01), Chr(0)) & Chr(0), Chr(0) & c01 & Chr(0))

By: JP

JP — Mon, 10 Sep 2012 19:57:50 +0000

@snb

Clever, but I prefer StrComp to get an exact match. Your function will return True for a substring match where one of the array elements contains an underscore. ex:

IsInArray_snb(Array("ID_12345", "ID_23432", "orange"), "ID")

By: snb

snb — Fri, 07 Sep 2012 07:42:27 +0000

I tested another method, using an ActiveX control.
Instead of searching in an array, you can look into the array that has heen assigned to a combobox or listbox.

So in Dick’s macro ‘testarray’, after filling the array aNames() I assigned that array to
Sheet1.Combobox1.List
or
Sheet1.Listbox1.List

Now the IsInArrray function can have the following structure

Function IsInArray_snb(c01 As String) As Boolean
With Sheet1.ComboBox1
.Value = c01
IsInArray_snb = .ListIndex > -1
End With
End Function

I’m not very disappointed by it’s speed.

By: snb

snb — Thu, 06 Sep 2012 13:11:36 +0000

I left a wrong email address.
So I corrected it.

The results of this function were half the time IsInArray_JP of IsInArray_DK produced.

Function IsInArray_snb(sn As Variant, c01 As String, Optional c02 As Boolean = True) As Boolean
IsInArray_snb = InStr(“_” & Join(Filter(sn, c01), “_”) & “_”, “_” & c01 & “_”)
End Function,

By: snb

snb — Wed, 05 Sep 2012 13:17:20 +0000

The results of this function were half the time IsInArray_JP of IsInArray_DK produced.

Function IsInArray_snb(sn As Variant, c01 As String, Optional c02 As Boolean = True) As Boolean
IsInArray_snb = InStr("_" & Join(Filter(sn, c01), "_") & "_", "_" & c01 & "_")
End Function

By: Kyle

Kyle — Tue, 24 Jul 2012 10:31:08 +0000

Really interesting post, there is also another method that hasn’t been mentioned. Recently I’ve been playing with the System.Collection classes from .Net that are usable from Excel – in particular the ArrayList – http://msdn.microsoft.com/en-us/library/system.collections.arraylist.aspx.

For large datasets it is much faster than dictionaries to fill and comes complete with a sort, binary search and standard search functions. The sort is relatively slow, but the binary searches are fast once sorted.