The value of the character variable x, is between 59-154 and missing = N/A.
I have tried the following code: stopifnot((df$x >= "59" & df$x <= "154") & is.na(df$x)) as well as the code here: stopifnot((df$x >= "59" & df$x <= "154") | df$x == "N/A")
Both codes return not all true, how do I get a code that is correct?