如何使用arrayformula“textjoin”（包括忽略空单元格）？

Question

I love textjoin because of the "ignore empty cells" capability, it's really clean. However, it won't work with ArrayFormula to auto-populate a column for me. So it seems a messier workaround is needed. This is what I have come up with. Does anyone know of a simpler solution?

Formula in cell A2 should combine values in cells B, C, & D with a delimiter, and not have any extra delimiters like leading or trailing _s, or _ _ in the middle.

+----------------------+------------+------+-----------+
|       NiceName       | first_name | year |  country  |
+----------------------+------------+------+-----------+
| Kaylee_1999          | Kaylee     | 1999 |           |
| Selma_2003_Indonesia | Selma      | 2003 | Indonesia |
| Babbette_Morocco     | Babbette   |      | Morocco   |
| Erhart_1985_Japan    | Erhart     | 1985 | Japan     |
| 1997_France          |            | 1997 | France    |
| Derward_1985_China   | Derward    | 1985 | China     |
+----------------------+------------+------+-----------+


=arrayformula(substitute(if(isblank(B2:B),,B2:B&"_")&if(isblank(C2:C),,C2:C)&if(isblank(D2:D),,"_"&D2:D),"__","_"))

screenshot of data & formula

Answer 1

For your current set of data try

=ArrayFormula(substitute(trim(transpose(query(transpose(B2:D),,rows(B2:B)))), " ", "_"))

and see if that works?

Answer 2

Here's a solution to deal with double first names if they crop up (or Country names with a space). Cell A2 :

=arrayformula(regexreplace({B2:B&if(C2:C<>"","_"&C2:C&"_","_")&D2:D},"^\_|\_$",))

I would also recommend adding an array_constrain to prevent the formula working all the way down the sheet.

=arrayformula(array_constrain(regexreplace({B2:B&if(C2:C<>"","_"&C2:C&"_","_")&D2:D},"^\_|\_$",),MAX(IF(B:D<>"",ROW(B:B))),1))

Also, to locate the formula in cell A1 , with a heading, you can use:

=arrayformula(array_constrain({"NiceName";regexreplace({B2:B&if(C2:C<>"","_"&C2:C&"_","_")&D2:D},"^\_|\_$",)},MAX(IF(B:D<>"",ROW(B:B))),1))