Is there a way to get the result column in the picture below? All i want to do is text join the Col1 if the corresponding Col2 belongs to the same groups (E.G. 1,2,3....). Reminded that I want to use arrayformula instead of dragging down the "normal" formula myself everytime.

CodePudding user response：

Use this formula
Or

CodePudding user response：

Great news for google-sheet lovers that google releases new lambda formulas. You can use BYROW() function to make it spill array. Try below formula.

=BYROW(C3:C9,LAMBDA(x,JOIN(",",FILTER(B3:B9,C3:C9=x))))

To refer entire column use FILTER() function for BYROW().

=BYROW(FILTER(C3:C,C3:C<>""),LAMBDA(x,JOIN(",",FILTER(B3:B,C3:C=x))))