Fill Empty Cells With The Same Value as Previous Cell in Google Sheet (Array Formula) [duplicate]

Question

I have a list of data that can be seen in this example:

https://docs.google.com/spreadsheets/d/1bRiupsmjfDRE9AgcM_5KJKAyxYKpQiMuyAGSoGaZYN0/edit?usp=sharing

1. Range A:B is the given data
2. Range D:E is the desired result

It is very easy to solve it without array formula. But Is there any array formula that can work it out? I need array formula so that i dont have to drag again and again when the data is added below.

Answer 1

use:

=INDEX({A:A, IF(A:A="",, VLOOKUP(ROW(B:B), 
 IF(B:B<>"", {ROW(B:B), B:B}), 2))})

Answer 2

For column B, put in C1

=ArrayFormula(lookup(row(B:B),row(B:B)/if(B:B<>"",1,0),B:B))