How to calculate the sum until 0 appears in a cell?

Question

excel

There is a column consisting of cells 0 and 1, how can you count the number of 1 until the first 0 is reached

. In the example, you need to get 4

Answer 1

For example, the range A1:A7
formula
=SUM(A1:INDEX($A$1:$A$7;MATCH(0;$A$1:$A$7;0)))

here the first argument of Match is the required zero cell.