Array.BinarySearch not finding an item

Question

3.00/5 (2 votes)

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VB

For Each t As Test In m_AllTests
Dim name As String = t.Name.ToString.ToLower.Trim
intIndexLocation = Array.BinarySearch(m_key, name)
If intIndexLocation >= 0 Then

My array search works fine except for one item which can't be found. intIndexLocation is -1 when it tries to search for that item. I have run my program through the debugger and verified that the item is present in the array. Can someone suggest another function or another way to solving this problem? Thank you.

Posted 18-Jan-11 3:16am

stevenandler

Updated 18-Jan-11 3:44am

Nish Nishant

v4

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3 solutions

Solution 1

The most common cause of this sort of problem (with string comparison/searching) is that you have trimmed your search-key but the strings in the array may not be trimmed. You can use an overload that lets you pass in a custom comparer, see:

http://msdn.microsoft.com/en-us/library/4ba2bttb.aspx[^]

Posted 18-Jan-11 3:26am

Nish Nishant

Solution 2

You should verify that
- The array in which you are searching is sorted, and
- The item you say is there but cannot be found is all lower case and trimmed.

You may want to post a larger fragment of your program, where you populate and sort m_key.

Posted 18-Jan-11 3:28am

dasblinkenlight

Comments

Espen Harlinn 18-Jan-11 10:04am

5+ Probable cause

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Prerak Patel · Accepted Answer · 2011-01-18T03:30:00

Solution 3

Is your array sorted?! (just in case)
As BinarySearch required sorted array to work properly.

Posted 18-Jan-11 3:30am

Prerak Patel

Comments

Espen Harlinn 18-Jan-11 10:04am

5+ Probable cause