INDEX MATCH to select items in list

[mdavid]

Hi, I have a column A3:A2249 of item numbers, item number appear multiple times in this column.
There's an index column B3:B107 where selected item numbers appear once.
If an item in column A appears also in column B, then insert "1" into column C else insert "0".
I think I can do that with the following formula in column C:
=IF(INDEX(??????,(MATCH(?,??:??,0)),"1","0") - but need help with the INDEX and MATCH, and maybe alot more!
Any help much appreciated.

 

[ETAF]

countif()
countif($A$3:$A$2249,B3)
copied down - will give a 1 if only in a once, and 0 if not found

OR include in a IF - to only give a 1 no matter how times it appears in A
=IF( countif($A$3:$A$2249,B3) >0, 1 , 0)

 

[mdavid]

Thanks for this Etaf,
I tried the 2nd option (=IF) - which is what I want.
Seems to be marking all the items in col B with a 1, instead of marking items in A that appear in B with a 1
I've uploaded the file with the results.
Thanks for your help

 

[ETAF]

sorry should have been
=IF( COUNTIF($A$3:$A$13,B3) >1, 1, 0)

count will find itself 1 - so >0 will always be 1

i have reduced the 1000's of rows to a small sample so easily seen

 

[mdavid]

Still having problems.
In the sample you sent me, the results are not consistent.
For value 4 in A:5 C:5 = 1 (which is correct), then for 4 in A10 & A11 C is marked 0,
Same for value 3 in A7:A9.

 

[pecoflyer]

If an item in column A appears also in column B, then insert "1" into column C else insert "0"

All items in col A appear in col B, so, the result is 1 everywhere as described in post #2. Your requirement is confusing ( BTW "1" is text and 1 is a number. Is this important?).
If you insert a number in col A that is not in col B then it returns a 0 ( see attached)
So ETAF's first solution is correct

 

[mdavid]

Thanks pecoflyer,
Sorry it's confusing. Found a solution.
Thanks for your help

 

[ETAF]

what was the solution , if different to my suggestion, please post as people searching may want to see the solution you found

 

[pecoflyer]

what was the solution , if different to mine suggestion, lease post as people searching may want to see the solution you found

I second the motion..