replace NA with 0 and all other values/text as 1

Question

airquality

    Ozone Solar.R Wind Temp Month Day
1      41     190  7.4   67     5   1
2      36     118  8.0   72     5   2
3      12     149 12.6   74     5   3
4             


        

Answer 1

Alternatively

airquality$Ozone[!is.na(airquality$Ozone)] <- 1L
airquality$Ozone[is.na(airquality$Ozone)] <- 0L