I have a dataframe in which one column, last_question, contains a list of variable names which are the last questions that various participants viewed on a survey.

test <- data.frame(
id <- c(1, 2, 3, 4, 5)
q1 <- c('Australia', 'Italy', 'Peru', 'China', 'Vermont')
q2 <-c('d',NA,'y',NA,'we')
q3 <- c(NA,'m',NA,NA,'op')
q4 <- c(123,NA,NA,NA,029)
last_question <-c(q1,q4,q2,q3,q4)
)

  id        q1   q2   q3 q4 last_question
1  1 Australia <NA> <NA> NA            q1
2  2     Italy <NA>    m NA            q4
3  3      Peru    y <NA> NA            q2
4  4     China <NA> <NA> NA            q4
5  5   Vermont   we   op 29            q4

I want to write a case_when formula that assigns the label “yes” to anyone for whom the answer to their last question is not null. Here is my expected output:

  id        q1   q2   q3 q4 last_question completion
1  1 Australia <NA> <NA> NA            q1        yes
2  2     Italy <NA>    m NA            q4         no
3  3      Peru    y <NA> NA            q2        yes
4  4     China <NA>  wsp NA            q4         no
5  5   Vermont   we   op 29            q4        yes

I can’t quite figure out how to tell the case_when formula to look at the contents of last_question and see variable names and then go assess those variables. I tried

test <-test%>%
mutate(completion=case_when(!is.na(get(last_question))~"yes",TRUE~"No"))

and I got this error:

Error in mutate():
ℹ In argument: completion = case_when(...).
Caused by error in case_when():
! Failed to evaluate the left-hand side of formula 4.
Caused by error in get():
! first argument has length > 1

Thank you in advance for your assistance!