counting number of occurences since last bad item

Hello,

I'm looking to get a formula which will count the number of entries based on criteria of number of good entries since last known bad entry. I have tried to explain this in the attached spreadsheet.

Column A→C = rawdata
Col A = Item
Col B = Good / Bad
Col C = Quantity

In column D i have added the expected result
D8 = 2 as opposed to a count of Col A = "Apples" and Col B result = "Good", a standard countif which would return 3 (Row 2,6 + 8) but as row 5 has Col B result as "Bad" i need to start the counter again to just include row 6 + 8

Administrative Note:

We would very much like to help you with your query, however the thread title does not really convey what your request is about. Tell us what you are trying to do, not how you think it should be done.

Please take a moment to amend your thread title. Make sure that the title properly explains your request. Your title should be explicit and not be generic (this includes function names used without an indication of what you are trying to achieve).

Please see Forum Rule #1 about proper thread titles and adjust accordingly. To edit the thread title, open the original post to edit and then click on Go Advanced (bottom right) to access the area where you can edit your title.

(Note: this change is not optional. No help to be offered until this moderation request has been fulfilled.)

1) Edit the title of the post, because as it is now it's against rule 1 of: https://www.excelforum.com/forum-rul...rum-rules.html
something like "counting number of occurences since last bad item" or may be adding "conditional counting number of occurences since last bad item" etc.


2) Use such array formula in D2 and copy it down:

Formula:

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But please do not forget about point 1) above.

3) Note that we are comparing column B values with Good_and_two_spaces - your data has such values in column B

**Array formulas are not entered in the same way as 'standard' formulas. Instead of pressing just ENTER, you first hold down CTRL and SHIFT, and only then press ENTER. If you've done it correctly, you'll notice Excel puts curly brackets {} around the formula (though do not attempt to manually insert these yourself).