Applies a LAMBDA to each row of an array and returns one value per row.

Syntax

=BYROW(array, lambda)

• Row sums

  =BYROW({1,2;3,4},LAMBDA(r,SUM(r))) → {3;7}

  Row sums.

• Row max

  =BYROW(B2:D6,LAMBDA(r,MAX(r))) → a max per row

  The largest value in each row.

• Join each row

  =BYROW(B2:D6,LAMBDA(r,TEXTJOIN("-",TRUE,r))) → joined rows

  Each row joined into one string.

• Replaces a helper column of per-row formulas with one spill.
• Combine with FILTER: FILTER(data,BYROW(data,LAMBDA(r,SUM(r))>100)).
• BYCOL for columns.

• The LAMBDA must return a single value per row.
• Requires Microsoft 365.