Menu
Essentially, I have a function that creates outputs of list(). I want my function to not create list(), but instead replace it with another value such as NULL or string. Is there a way to determine if a variable is assigned the empty list, list()?
858
Description. NULL represents the null object in R. NULL is used mainly to represent the lists with zero length, and is often returned by expressions and functions whose value is undefined.
A string in R can be created using single quotes or double quotes. We can create an empty string with empty_str = "" or an empty character vector with empty_chr = character(0) . Both have class “character” but the empty string has length equal to 1 while the empty character vector has length equal to zero.
If you check length(vec) , we know the length of our vector is also 0, meaning that our vector, vec , is empty.
The list::empty() is a built-in function in C++ STL is used to check whether a particular list container is empty or not. This function does not modifies the list, it simply checks whether a list is empty or not, i.e. the size of list is zero or not.
Empty list is empty. It has no elements, but is still a list. List with no elements has length 0.
a = list() if(length(a) == 0) { .... } !is.null(listname) & class(listname) != "NULL" & class(listname) != "logical" & length(listname) != 0 If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
