With 3 columns how would I apply a formula to the first 2 and display the result in the 3rd?

问题

In Google Sheets I want to get the sum of the first 2 columns and display that result in the 3rd column all the way down. Like this:

I'm hoping for a solution that does this in one step. As I have many rows.

Edit: I am aware of this question: Apply formula to the entire column and it appears to only cover part of what I am asking.

回答1:

Try:

=arrayformula(if(A2:A<>"",ADD(A2:A,B2:B),""))

来源：https://stackoverflow.com/questions/40497946/with-3-columns-how-would-i-apply-a-formula-to-the-first-2-and-display-the-result