Google Sheets; arrayformular(if x=1 write 1 BUT if x=2 write 2)

I've got this working: =IF(AND(B3 = "Hverdag");"Hverdag";IF(AND(B3 = "Weekend");"Weekend";""))

What I want is: =ARRAYFORMULA(IF(AND(B3:B = "Hverdag");"Hverdag";IF(AND(B3:B = "Weekend");"Weekend";"")))

Did I miss something or is there a better way doing this math?