System.Array.Bi narySearch

[Sueffel]

Okay, I can certinatly use a For..Next loop to find the specified info I
need, but I'm thinking the BinarySearch will be faster, if I can get it
working LOL

Anyhew, got an array, may have 5 or 5,000 elements, and I need to find the
string, say it's "Start here".

I've tried this:
Dim MyObj as Object = "Start Here"
Dim I as Integer = System.Array.Bi narySearch(MyAr r,MyObj)

and I get stuff like -1267 (Or size of array)

Frustraiting,
Sueffel

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[Armin Zingler]

"Sueffel" <so*****@somewh ere.com> schrieb

Okay, I can certinatly use a For..Next loop to find the specified
info I need, but I'm thinking the BinarySearch will be faster, if I
can get it working LOL

Anyhew, got an array, may have 5 or 5,000 elements, and I need to
find the string, say it's "Start here".

I've tried this:
Dim MyObj as Object = "Start Here"
Dim I as Integer = System.Array.Bi narySearch(MyAr r,MyObj)

and I get stuff like -1267 (Or size of array)

Where is the problem? Read the description of the return value in the docs
for BinarySearch.
--
Armin

[William Ryan eMVP]

Are you sure your array is sorted?
"Sueffel" <so*****@somewh ere.com> wrote in message
news:OX******** ******@TK2MSFTN GP09.phx.gbl...

Okay, I can certinatly use a For..Next loop to find the specified info I
need, but I'm thinking the BinarySearch will be faster, if I can get it
working LOL

Anyhew, got an array, may have 5 or 5,000 elements, and I need to find the
string, say it's "Start here".

I've tried this:
Dim MyObj as Object = "Start Here"
Dim I as Integer = System.Array.Bi narySearch(MyAr r,MyObj)

and I get stuff like -1267 (Or size of array)

Frustraiting,
Sueffel

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Version: 6.0.580 / Virus Database: 367 - Release Date: 2/6/2004

[Cor]

Hi Sueffel,

Are you an old Cobol programmer who had to do with the magic of the binary
search in that.

Why should a binary Search be faster.

Did you already look at the array.indexof method?

Cor

Okay, I can certinatly use a For..Next loop to find the specified info I
need, but I'm thinking the BinarySearch will be faster, if I can get it
working LOL

Anyhew, got an array, may have 5 or 5,000 elements, and I need to find the
string, say it's "Start here".

I've tried this:
Dim MyObj as Object = "Start Here"
Dim I as Integer = System.Array.Bi narySearch(MyAr r,MyObj)

and I get stuff like -1267 (Or size of array)

[Sueffel]

To resond to Armin first:

My array length is 1236, the BinarySearch is returning -1231, and in this
case I know that the string I'm looking for is at element 11, so there's no
correlation. I have followed the example to the letter, and this is waht I
get. I'm getting frustraited with this...

And now to William:

Here's my Code, verbatum:

'Air Code'
System.Array.So rt(FST) 'FST is my array with 1236 Elements in it
Dim MySearchObj As Object = "MD5 message digest"
I= System.Array.Bi narySearch(FST, MySrchObj)
MsgBox(I)
'*******'

The only thting I can figure, is the string in the file is:
"MD5 message digest filename
"

problem is, .NET is trimming the end, so, I need to do a search only using
part of the string. I can do this very easily with a For...Next loop, but
with 5,000 elements, we can see that this is probably not the most efficient
way of doing this.

Thanks again,
Sueffel
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[Herfried K. Wagner [MVP]]

* "Sueffel" <so*****@somewh ere.com> scripsit:

Okay, I can certinatly use a For..Next loop to find the specified info I
need, but I'm thinking the BinarySearch will be faster, if I can get it
working LOL

Anyhew, got an array, may have 5 or 5,000 elements, and I need to find the
string, say it's "Start here".

I've tried this:
Dim MyObj as Object = "Start Here"
Dim I as Integer = System.Array.Bi narySearch(MyAr r,MyObj)

and I get stuff like -1267 (Or size of array)

<msdn>
Return Value

The index of the specified value in the specified array, if value is
found.

-or-

A negative number, which is the bitwise complement of the index of the
first element that is larger than value, if value is not found and value
is less than one or more elements in array.

-or-

A negative number, which is the bitwise complement of (the index of the
last element + 1), if value is not found and value is greater than any
of the elements in array.
</msdn>

--
Herfried K. Wagner [MVP]
<http://www.mvps.org/dotnet>

[Sueffel]

"Cor" <no*@non.com> wrote in message
news:eQ******** ******@TK2MSFTN GP09.phx.gbl...

Hi Sueffel,

Are you an old Cobol programmer who had to do with the magic of the binary
search in that.

Why should a binary Search be faster.

Did you already look at the array.indexof method?

Cor

Okay, I can certinatly use a For..Next loop to find the specified info I
need, but I'm thinking the BinarySearch will be faster, if I can get it
working LOL

Anyhew, got an array, may have 5 or 5,000 elements, and I need to find the string, say it's "Start here".

I've tried this:
Dim MyObj as Object = "Start Here"
Dim I as Integer = System.Array.Bi narySearch(MyAr r,MyObj)

and I get stuff like -1267 (Or size of array)

No, no cobol programmer, but, binary is faster than string or hex searching.
nature of computing. I'm going to look at indexOf though, that may be my
answer.

Thanks again everyone,
Sueffel
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[Jay B. Harlow [MVP - Outlook]]

Sueffel,
You do realize that BinarySearch does an exact match:

Dim MySearchObj As Object = "MD5 message digest"
Does element 11 have "MD5 message digest" exactly, if it does its index
should be returned.

Or does it have "MD5 message digest
filename", in which case it does not match, and you get the negative number.

As both the extra spaces and filename will not allow it to match!

In your For Next, I take it you are using String.StartsWi th to get an
approximate match?

Hope this helps
Jay

"Sueffel" <so*****@somewh ere.com> wrote in message
news:OY******** ******@TK2MSFTN GP12.phx.gbl... To resond to Armin first:

My array length is 1236, the BinarySearch is returning -1231, and in this
case I know that the string I'm looking for is at element 11, so there's no correlation. I have followed the example to the letter, and this is waht I get. I'm getting frustraited with this...

And now to William:

Here's my Code, verbatum:

'Air Code'
System.Array.So rt(FST) 'FST is my array with 1236 Elements in it
Dim MySearchObj As Object = "MD5 message digest"
I= System.Array.Bi narySearch(FST, MySrchObj)
MsgBox(I)
'*******'

The only thting I can figure, is the string in the file is:
"MD5 message digest filename
"

problem is, .NET is trimming the end, so, I need to do a search only using
part of the string. I can do this very easily with a For...Next loop, but
with 5,000 elements, we can see that this is probably not the most efficient way of doing this.

Thanks again,
Sueffel
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[Sueffel]

Indexof works like a wet dream!

Thanks again everyone,
Sueffel
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