Compare two columns and extract differences

The formula is now an array formula. See the curly brackets, they tell you it is an array formula. Don't enter the curly brackets yourself, they appear if you enter it correctly, like this:

{=INDEX($A$2:$A$14, SMALL(IF(COUNTIF($B$2:$B$10, $A$2:$A$14)=0, MATCH(ROW($A$2:$A$14), ROW($A$2:$A$14)), ""), ROW(A1)))}

How to copy array formula

Compare values between two columns and filter values existing in only one column

Select cell E3.
Copy (Ctrl + c).
Select cell range E4:E8.
Paste (Ctrl + v).

Explaining array formula in cell E3

Compare values between two columns and extract differences evaluate formula

I recommend the "Evaluate Formula" tool when you want to understand, troubleshoot or examine a specific formula.

Select the cell containing the formula you want to evaluate. Go to tab "Formulas" on the ribbon, press with left mouse button on the "Evaluate Formula" button, see image above.

Compare values between two columns and extract differences evaluate formula dialog box

A dialog box appears, it shows the formula and the button "Evaluate" below the formula allows you to go through the formula calculations step by step.

Step 1 - Count values in column C based on values in column B

Compare values between two columns and extract differences COUNTIF function

The COUNTIF function lets you count values based on a condition, however, it is also possible to use multiple conditions but then the function returns an array of values instead of a single value.

This is what makes the formula an array formula. Here are the arguments in the COUNTIF function:

COUNTIF(range, criteria)

COUNTIF($C$3:$C$11, $B$3:$B$15)

becomes

COUNTIF({"BB"; "DD"; "EE"; "HH"; "II"; "JJ"; "KK"; "VV"; "PP"}, $B$3:$B$15)

becomes

COUNTIF({"BB"; "DD"; "EE"; "HH"; "II"; "JJ"; "KK"; "VV"; "PP"}, {"AA"; "CC"; "DD"; "EE"; "GG"; "HH"; "II"; "JJ"; "KK"; "MM"; "NN"; "OO"; "PP"})

and returns the following array of values:

{0; 0; 1; 1; 0; 1; 1; 1; 1; 0; 0; 0; 1}

The position of each value in the array is very important, they make it possible to identify and extract the values we want. The position of each value in the array corresponds to the value in column B, see image above.

A 0 (zero) means that the value in column B is not found in column C. 1 is that the value in column B is found once in column C.

Step 2 - Check if they are equal to 0 (zero)

Compare values between two columns and extract differences boolean values

The equal sign checks if the values are equal to 0 (zero) and returns the boolean values TRUE or FALSE.

COUNTIF($C$3:$C$11, $B$3:$B$15)=0

becomes

{0; 0; 1; 1; 0; 1; 1; 1; 1; 0; 0; 0; 1}=0

and returns

{TRUE; TRUE; FALSE; FALSE; TRUE; FALSE; FALSE; FALSE; FALSE; TRUE; TRUE; TRUE; FALSE}

Step 3 - If they are equal to zero, return the corresponding relative row number

Compare values between two columns and extract differences if function

The IF function allows you to return a specific value if the logical test is TRUE and another value if FALSE.

IF(logical_test, [value_if_true], [value_if_false])

IF(COUNTIF($C$3:$C$11, $B$3:$B$15)=0, MATCH(ROW($B$3:$B$15), ROW($B$3:$B$15)), "")

becomes

IF({TRUE; TRUE; FALSE; FALSE; TRUE; FALSE; FALSE; FALSE; FALSE; TRUE; TRUE; TRUE; FALSE}, MATCH(ROW($B$3:$B$15), ROW($B$3:$B$15)), "")

The MATCH and ROW functions create an array from 1 to 11 which we then will use to extract the correct value from cell range B3:B15.

MATCH(ROW($B$3:$B$15), ROW($B$3:$B$15))

becomes

MATCH({3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15}, {3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15})

and returns

{1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13}.

Step 4 - Return the k-th smallest row number

The SMALL function returns the k-th smallest number from an array or cell range.

SMALL(IF(COUNTIF($C$3:$C$11, $B$3:$B$15)=0, MATCH(ROW($B$3:$B$15), ROW($B$3:$B$15)), ""), ROWS($A$1:A1))

beomes

SMALL({1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13}, ROWS($A$1:A1))

The ROWS function counts the number of rows in a given cell reference. The cell ref in this example expands when you copy the cell and paste to cells below. This makes the SMALL function return a new number in each cell.

SMALL({1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13}, ROWS($A$1:A1))

becomes

SMALL({1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13}, 1)

and returns 1.

Step 5 - Return value

Compare values between two columns and extract differences index function

The INDEX function returns a value or multiple values based on a row and/or column number.

INDEX($B$3:$B$15, SMALL(IF(COUNTIF($C$3:$C$11, $B$3:$B$15)=0, MATCH(ROW($B$3:$B$15), ROW($B$3:$B$15)), ""), ROWS($A$1:A1)))

becomes

INDEX($B$3:$B$15, 1)

and returns "AA" in cell E3.

Get the Excel file

Filter-values-existing-in-column-1-but-not-in-column-2.xlsx

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Comments (3)

3 Responses to “Compare two columns and extract differences”

Bruno says:

December 1, 2013 at 7:42 pm

Hi Oscar,
I started with the solution provided here for obtaining values existing only in one of two lists. I know that, for an ordered done job, one should tend use excel in a 'database-like' fashion, with columns as field and rows for data, and so I do.
Anyway, it happened that I had the necessity to have two lists of data to compare,but they spread horizontally. I also read your solutions for filtering values existing in different ranges, but since I was in a hurry,I adapted the formulas provided here, and wanted to share my solution.Here is the two alternative formulas that do the job in a 'column fashion':
Let's say we have two list to compare in ranges G1:V1 and G2:V2 respectively. In the result's range, I put the formula:
={INDEX($G$1:$V$1;;SMALL(IF(COUNTIF($G$2:$V$2;$G$1:$V$1)=0;MATCH(COLUMN($G$1:$V$1);COLUMN($G$1:$V$1));"");COLUMN(A1)))}
or, alternatively (thanks to another solution found here):
={INDEX($G$1:$V$1; SMALL(IF(ISERROR(MATCH($G$1:$V$1; $G$2:$V$2; 0)); (COLUMN($G$1:$V$1)-MIN(COLUMN($G$1:$V$1))+1); ""); COLUMN(A$1:A$65536)))} . I noticed that, if I use the same size for all three ranges (lists and results), I end up with having some zeroes padding the 2nd result range (Missing data in List 1), whether I use vertical or horizontal lists.
as you can see from the image I provide here:
https://s12.postimg.org/jp0p9y6st/Filter_values_existing_in_column_1_but_not_in_co.jpg
I am wondering how those zeroes appear ?
I uploaded the example excel file.

Reply
- Oscar says:
  
  December 3, 2013 at 12:44 pm
  
  Bruno,
  
  You are comparing 4 blank cells ($G$2:$V$2) with the values in cell range $G$1:$V$1. Since there are no blank cells the formula returns the blank cells. The INDEX function then returns 0.
  
  Try this formula in cell G2:
  =INDEX($G$2:$O$2, , SMALL(IF(COUNTIF($G$1:$S$1, $G$2:$O$2)=0, MATCH(COLUMN($G$2:$O$2), COLUMN($G$2:$O$2)), ""), COLUMN(A1)))
hadi says:

February 17, 2016 at 10:27 am

Hi.
I have excel file:
code bookname language bookcode id
1 book1 en 100
2 book2 fa 101
3 book1 ar 102
4 book3 en 103
5 book2 fa 104
6 book4 az 105
...

i have want to filter by book & language columns and when two columns are exist, value of id column equal is last row value of code column. for example:
book2 is true but book1 is not true. so id book1 = 104

thanks

Reply

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