I assume this is a common problem but haven't been able to find an answer to this question. Let's assume I have the following list:
myList <- list(
apple = 15,
orange = NULL
)
I want to test its vectors for values, although I cannot be sure that these vectors exist when i perform the test.
if(myList$apple > 1) print("Y")
if(myList$orange > 1) print("Y")
if(myList$banana > 1) print("Y")
This obviously doesn't work
Error in if (myList$orange > 1) print("Y") : argument is of length zero
Error in if (myList$banana > 1) print("Y") : argument is of length zero
However, for I want to avoid nested testing with exists() for reasons that would require too much detail. So my question is: Can a test on a variable that possibly doesn't exist be performed in only one conditional statement?
Thanks
Aucun commentaire:
Enregistrer un commentaire