Is object named?Source:
is_named()is a scalar predicate that checks that
namesattribute and that none of the names are missing or empty (
is_named()but always returns
TRUEfor empty vectors, even those that don't have a
namesattribute. In other words, it tests for the property that each element of a vector is named.
is_named2()composes well with
have_name()is a vectorised variant.
is_named2() are scalar predicates that
have_name() is vectorised and returns
a logical vector as long as the input.
# is_named() is a scalar predicate about the whole vector of names: is_named(c(a = 1, b = 2)) #>  TRUE is_named(c(a = 1, 2)) #>  FALSE # Unlike is_named2(), is_named() returns `FALSE` for empty vectors # that don't have a `names` attribute. is_named(list()) #>  FALSE is_named2(list()) #>  TRUE # have_name() is a vectorised predicate have_name(c(a = 1, b = 2)) #>  TRUE TRUE have_name(c(a = 1, 2)) #>  TRUE FALSE # Empty and missing names are treated as invalid: invalid <- set_names(letters[1:5]) names(invalid) <- "" names(invalid) <- NA is_named(invalid) #>  FALSE have_name(invalid) #>  FALSE TRUE FALSE TRUE TRUE # A data frame normally has valid, unique names is_named(mtcars) #>  TRUE have_name(mtcars) #>  TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE # A matrix usually doesn't because the names are stored in a # different attribute mat <- matrix(1:4, 2) colnames(mat) <- c("a", "b") is_named(mat) #>  FALSE names(mat) #> NULL