The other day, while I was putting my kids to sleep, this idea came to me. How do I check if a cell contains a palindrome, using Excel formulas?
Next morning, I wrestled with excel for about 20 minutes and boom, the formula is ready.
Here is how it works:
If you enter a word or phrase in column B, it would tell you whether it is a palindrome or not.
But what is a palindrome?
A palindrome is a word, phrase, verse, or sentence that reads the same backward or forward. For example: A man, a plan, a canal, Panama!
[definition from palindromelist.net]
So, to check if a cell contains palindrome, we need to reverse the cell contents and see if both original and reverse are the same.
For example if B1 contains MAN, then the reverse would be NAM and hence MAN is not a palindrome.
But how do we write a formula to check if a cell has palindrome?
- Assuming B1 contains the word (or phrase), the first step is to clean it. That means, we need to remove any spaces, commas, exclamation marks & other punctuation symbols. So a phrase like “Cigar? Toss it in a can. It is so tragic.” would become “CigarTossitinacanItissotragic”.
- The next step is to match this cleaned text (lets say this will be C1) with the reverse of it.
- But there is no reverse formula. So we use MID() to extract one letter at a time and match it with the corresponding letter from end. (ie first letter with last letter, second letter with second last letter etc.)
- To do this, we use,
MID(C1,ROW(OFFSET($A$1,,,LEN(C1))),1=MID(C1,LEN(C1)-ROW(OFFSET($A$1,,,LEN(C1)))+1,1) - The left portion of this formula would give individual letters in C1 in left to right order and the right portion would give same in reverse order.
- We wrap this in a lovely SUMPRODUCT formula so that we can check for palindrome-ness of B1 using
=IF( SUMPRODUCT( ( MID(C1,ROW(OFFSET($A$1,,,LEN(C1))),1) = MID(C1,LEN(C1)-ROW(OFFSET($A$1,,,LEN(C1)))+1,1)) + 0 ) = LEN(C1), "It’s a Palindrome", "Nah!")
How does this formula work?
Well, that is your weekend homework. Go figure.
One more homework if you are game
If you feel like playing with words, here is another challenge.
How would you test if a cell contains alliteration?
(Alliteration here is defined as sentence where all words begin with same letter)
Go ahead and post your answers using comments.
Download Palindrome Test Excel Workbook
Click here to download the excel workbook and see the palindrome test formulas yourself.
Learn more about Excel Array Formulas
Array formulas are a special class of Excel formulas that can provide powerful results with little work. We have a huge collection of array formula examples on chandoo.org. Go thru below list and see how deep the rabit hole goes.
SUMPRODUCT Formula and how to use it
Advanced SUMPRODUCT Queries
Use Array Formulas to check if a list is sorted
Calculating sum of digits in a number using formulas
Check if a number is Prime using array formulas
More… Excel Array Formulas – Examples & Demos
PS: Monday is our (Indian) Independence Day. So I will see you again on Tuesday.
PPS: On Tuesday, we will be announcing our Excel Formula Crash Course. Get ready.
21 Responses to “How to Filter Odd or Even Rows only? [Quick Tips]”
Infact, instead of using =ISEVEN(B3), how about to use =ISEVEN(ROW())
So it takes away any chance of wrong referencing.
I like Daily Dose of Excel
I like it.
Just a heads up, you do need to have the Analysis ToolPak add-in activated to use the ISEVEN / ISODD functions. An alternative to ISEVEN would be:
=MOD(ROW(),2)=0
rather than use a formula, couldn't you enter "true" in first cell and "false" in the second and drag it down and than filter on true or false.
Just for clarification, is Ashish looking to filter by even or odd Characters or rows?
so many functions to learn!
Nice support by chandoo and team as a helpdesk. Give us more to learn and make us awesome. Always be helpful.......
In case you want to delete instead of filter,
IF your data is in Sheet1 column A
Put this in Sheet2 column A and drag down
=OFFSET(Sheet1!A$1,(ROWS($1:1)-1)*2,,)
(This is to delete even rows)
To delete odd rows :
=OFFSET(Sheet1!A$2,(ROWS($1:1)-1)*2,,)
If your numbered cells did not correspond to rows, the answer would be even simpler:
=MOD([cell address],2), then filter by 0 to see evens or 1 to see odds.
I sometimes do this using an even simpler method. I add a new column called "Sign" and put the value of 1 in the first row, say cell C2 if C1 contains the header. Then in C3 I put the formula =-1 * C2, which I copy and paste into the rest of the rows (so C4 has =-1 * C3 and so forth). Now I can just apply a filter and pick either +1 or -1 to see half the rows.
Another way, which works if I want three possibilities: in C2 I put the value 1, in C3 I put the value 2, in C4 I put the value 3, then in C5 I put the formula =C2 then I copy C5 and paste into all the remaining rows (so C6 gets =C3, C7 gets =C4, etc.). Now I can apply a filter and pick the value 1, 2, or 3 to see a third of the rows.
Extending this approach to more than 3 cases is left as an exercise for the reader.
Another way =MOD(ROW();2). In this case, must to choose betwen 1 and 0.
[...] How to Filter Even or Odd rows only [...]
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http://www.handycss.com/tips/odd-or-even-rows/
Thanks for the tip, it worked like magic, saved having to delete row by row in my database.
Thanks!
Thankssssssssssssssss
Hi Chandoo- First of all thanks for the trick. It helped me a lot. Here I have one more challenge. Having filtered the data based on odd. I want to paste data in another sheet adjacent to it. How can I do that?
For Example-
A 1 odd
B 3 odd
C 4 even
D 6 even
I have fileted the above data for odd and want to copy the "This is odd number" text in adjacent/next sheet here. How can I do that. After doing this my data should look like this
A 1 odd This is odd number
B 3 odd This is odd number
C 4 even
D 6 even
Hi! Could you please help me find a formula to filter by language?
Thank you!
Chandoo SIR,
I HAVE A DATA IN EXCEL ROWS LIKE BELOW IS THERE ANY FORMULA OR A WAY WHERE I CAN INSTRUCT I CAN MAKE CHANGES , MEANS I WANT TO WRITE ONLY , THE FIG IS FRESH, BUT IN BELOW ROW IT WILL AUTOMATICALLY TAKE THE SOME WORDS FROM FIGS AND MAKE IN PLURAL FORM , WHILE USING '' ARE'' LIKE BELOW
The fig is fresh - row 1
Figs are fresh - row 2
The Pomegranate is red - row 3
Pomegranates are red - row 4
=IF(EVEN(A1)=A1,"EVEN - do something","ODD - do something else") with iferron (for blank Cell)