A while ago (well more than 3 years ago), I wrote about an array formula based technique to check if a list of values have any duplicates in them.
Today, lets learn a simpler formula to check if a list has duplicate numbers.
Assuming you have some numbers in a range B4:B10 as shown below,
You can use COUNTIF & MODE formulas to check if the list has any duplicates, like this:
=IF(COUNTIF($B$4:$B$10,MODE($B$4:$B$10))>1, "List has duplicates", "No duplicates")
How does it work?
MODE formula gives us the most frequently occurring number in a list. Then, we use COUNTIF to see how many times this number occurs in a list.
In a list with no duplicates mode value occurs only 1 time. If a list has duplicate numbers, then count of mode would be more than 1. That is what the IF formula checks for and then prints appropriate message.
See this example:
[Embedded Excel, if you can not see it, click here]
Play with below embedded Excel file to understand the technique. You can modify numbers or formula.
Or Download this Example
Click here to download the example workbook and play with it.
How do you check if a list has duplicates?
For text values, I use the array formula technique described here. For numeric values, I prefer MODE + COUNTIF combination because it is easy to write & explain.
What about you? How do you check if a list has duplicates? Which formulas do you use? Please share your techniques using comments.
More on Duplicates & Unique values
If we analyze the time an analyst spends on various things, we would realize,
- 30% of time cleaning data (removing duplicates etc.)
- 30% of time actual analysis
- 30% of time drinking coffee
- 10% of time actual presentation
On a more serious note, if you want to learn various techniques to deal with duplicate values, read on:
- Extracting unique values from a list in Excel using formulas
- Extracting unique values from a list using Pivot tables
- Count the number of values in a list (excluding duplicates)
- Quickly compare 2 lists and check for duplicates
- Removing duplicate values quickly
- Avoiding duplicate data entry using Data Validation
6 Responses to “Make VBA String Comparisons Case In-sensitive [Quick Tip]”
Another way to test if Target.Value equal a string constant without regard to letter casing is to use the StrCmp function...
If StrComp("yes", Target.Value, vbTextCompare) = 0 Then
' Do something
End If
That's a cool way to compare. i just converted my values to strings and used the above code to compare. worked nicely
Thanks!
In case that option just needs to be used for a single comparison, you could use
If InStr(1, "yes", Target.Value, vbTextCompare) Then
'do something
End If
as well.
Nice tip, thanks! I never even thought to think there might be an easier way.
Regarding Chronology of VB in general, the Option Compare pragma appears at the very beginning of VB, way before classes and objects arrive (with VB6 - around 2000).
Today StrComp() and InStr() function offers a more local way to compare, fully object, thus more consistent with object programming (even if VB is still interpreted).
My only question here is : "what if you want to binary compare locally with re-entering functions or concurrency (with events) ?". This will lead to a real nightmare and probably a big nasty mess to debug.
By the way, congrats for you Millions/month visits 🙂
This is nice article.
I used these examples to help my understanding. Even Instr is similar to Find but it can be case sensitive and also case insensitive.
Hope the examples below help.
Public Sub CaseSensitive2()
If InStr(1, "Look in this string", "look", vbBinaryCompare) = 0 Then
MsgBox "woops, no match"
Else
MsgBox "at least one match"
End If
End Sub
Public Sub CaseSensitive()
If InStr("Look in this string", "look") = 0 Then
MsgBox "woops, no match"
Else
MsgBox "at least one match"
End If
End Sub
Public Sub NotCaseSensitive()
'doing alot of case insensitive searching and whatnot, you can put Option Compare Text
If InStr(1, "Look in this string", "look", vbTextCompare) = 0 Then
MsgBox "woops, no match"
Else
MsgBox "at least one match"
End If
End Sub