arrayformula sum in Google spreadsheet

Question

How do you arrayformula() a sum() such as:

=sum(A1:H1)

I need to go down 1000 rows.

Answer 1

If you want to be able to add rows and sum to the last row for all values in A1:H, you can use:

 =ArrayFormula(SUMIF(IF(COLUMN(A1:H1),ROW(A1:A)),ROW(A1:A),A1:H))

Alternatively, if you want be be able to add rows and columns to the spreadsheet and sum to the last of both this can also be done. Paste the following code into any cell and it will create a column of summed values for all cells in each row below and to the right of pasted cell:

=arrayformula(SUMIF(IF(COLUMN(indirect(concatenate(REGEXREPLACE(address(row(),column()+1),"[^[:alpha:]]", ""),VALUE(REGEXREPLACE(address(row(),column()),"[^[:digit:]]", "")),":",VALUE(REGEXREPLACE(address(row(),column()),"[^[:digit:]]", ""))))),ROW(indirect(concatenate(REGEXREPLACE(address(row(),column()+1),"[^[:alpha:]]", ""),VALUE(REGEXREPLACE(address(row(),column()),"[^[:digit:]]", "")),":",REGEXREPLACE(address(row(),column()+1),"[^[:alpha:]]", ""))))),ROW(indirect(concatenate(REGEXREPLACE(address(row(),column()+1),"[^[:alpha:]]", ""),VALUE(REGEXREPLACE(address(row(),column()),"[^[:digit:]]", "")),":",REGEXREPLACE(address(row(),column()+1),"[^[:alpha:]]", "")))),indirect(concatenate(concatenate(REGEXREPLACE(address(row(),column()+1),"[^[:alpha:]]", ""),VALUE(REGEXREPLACE(address(row(),column()),"[^[:digit:]]", "")),":"),address(rows($A:$A),columns($1:$1))))))