Excel formula to check for duplicate words - excel

Question

I require an excel formula to check if any words are being duplicated in any column in a row. My sample row is below columns separated by a ','.
Column No: E221, F221, G221, H221
Column Text: Sam, John/Sam/Smith, Smith, Kyle
Above Sam & Smith names are being repeated so the words should be highlighted in red.
Excel File Link:
https://docs.google.com/spreadsheets/d/1D6PZWtbk_2IVEA4l1noFzKRFu0quXSTAewmL41xOnlo/edit?usp=sharing

Answer 1

I think this does the job (assuming you have your data in B1:F1):-
=if(b1="",0,
SUM(1-(ISERROR(FIND(MID("/"&B1&"/",FIND("|",SUBSTITUTE("/"&B1&"/","/","|",{1;2;3;4;5;6})),FIND("|",SUBSTITUTE("/"&B1&"/","/","|",{2;3;4;5;6;7}))-FIND("|",SUBSTITUTE("/"&B1&"/","/","|",{1;2;3;4;5;6}))+1),"/"&$A$1:A$1&"/"))))
+SUM(1-(ISERROR(FIND(MID("/"&B1&"/",FIND("|",SUBSTITUTE("/"&B1&"/","/","|",{1;2;3;4;5;6})),FIND("|",SUBSTITUTE("/"&B1&"/","/","|",{2;3;4;5;6;7}))-FIND("|",SUBSTITUTE("/"&B1&"/","/","|",{1;2;3;4;5;6}))+1),"/"&C$1:$G$1&"/"))))
)
It extracts each name in each cell and tries to match it with all other cells but because it uses array constants you can't use it directly in conditional formatting: you would have to put this in (say) B2:F2 and base your conditional formatting on it, or else use an even longer formula.
It's an array formula, so need to enter it with Ctrl Shift Enter
Here is an improved formula. Previously I was matching cells to the left and right of the current cell: this one matches all cells including the current cell and subtracts the number of matches where the current cell matches with itself:-
=if(b1="",0,
SUM(1-(ISERROR(FIND(MID("/"&B1&"/",FIND("|",SUBSTITUTE("/"&B1&"/","/","|",{1;2;3;4;5;6})),FIND("|",SUBSTITUTE("/"&B1&"/","/","|",{2;3;4;5;6;7}))-FIND("|",SUBSTITUTE("/"&B1&"/","/","|",{1;2;3;4;5;6}))+1),"/"&$B$1:$F$1&"/"))))
-(LEN(B1)-LEN(SUBSTITUTE(B1,"/",""))+1)
)
If you wanted a formula that you could use directly in conditional formatting, I think you would have to enumerate all possible matches for all possible substrings separately which is rather tedious:-
=if(b1="",0,
SUM(
1-(ISERROR(FIND(MID("/"&B1&"/",FIND("|",SUBSTITUTE("/"&B1&"/","/","|",1)),FIND("|",SUBSTITUTE("/"&B1&"/","/","|",2))-FIND("|",SUBSTITUTE("/"&B1&"/","/","|",1))+1),"/"&$B$1:$F$1&"/"))),
1-(ISERROR(FIND(MID("/"&B1&"/",FIND("|",SUBSTITUTE("/"&B1&"/","/","|",2)),FIND("|",SUBSTITUTE("/"&B1&"/","/","|",3))-FIND("|",SUBSTITUTE("/"&B1&"/","/","|",2))+1),"/"&$B$1:$F$1&"/"))),
1-(ISERROR(FIND(MID("/"&B1&"/",FIND("|",SUBSTITUTE("/"&B1&"/","/","|",3)),FIND("|",SUBSTITUTE("/"&B1&"/","/","|",4))-FIND("|",SUBSTITUTE("/"&B1&"/","/","|",3))+1),"/"&$B$1:$F$1&"/"))),
1-(ISERROR(FIND(MID("/"&B1&"/",FIND("|",SUBSTITUTE("/"&B1&"/","/","|",4)),FIND("|",SUBSTITUTE("/"&B1&"/","/","|",5))-FIND("|",SUBSTITUTE("/"&B1&"/","/","|",4))+1),"/"&$B$1:$F$1&"/"))),
1-(ISERROR(FIND(MID("/"&B1&"/",FIND("|",SUBSTITUTE("/"&B1&"/","/","|",5)),FIND("|",SUBSTITUTE("/"&B1&"/","/","|",6))-FIND("|",SUBSTITUTE("/"&B1&"/","/","|",5))+1),"/"&$B$1:$F$1&"/"))),
1-(ISERROR(FIND(MID("/"&B1&"/",FIND("|",SUBSTITUTE("/"&B1&"/","/","|",6)),FIND("|",SUBSTITUTE("/"&B1&"/","/","|",7))-FIND("|",SUBSTITUTE("/"&B1&"/","/","|",6))+1),"/"&$B$1:$F$1&"/"))))
-(LEN(B1)-LEN(SUBSTITUTE(B1,"/",""))+1)
)