How do I make a column that compares whether the entry in the one column matches the entry in anothe-CodePudding

I'm working on this excel problem and I ran into an issue I'm not sure how to solve.

In my Google Sheets document, column A shows all the customers that placed an order in August, while column B shows all the customers that placed an order in September. I need column C to look at all the values in August and all the values in September and if there is a match to return "retained customer" and if there isn't to return "new customer". I have tried combining the if and vlookup function, in something like =if(vlookup(B1,A:A,1,False), 'retained cusomer', 'new cusomer'), but I keep getting an error.

Does anyone have any suggestions on what I can do to fix it? Thank you so much!

CodePudding user response：

try:

=INDEX(IF(REGEXMATCH(B:B; TEXTJOIN("|"; 1; A:A)); "retained customer"; "new customer"))