• is_named() is a scalar predicate that checks that x has a names attribute and that none of the names are missing or empty (NA or "").

  • is_named2() is like is_named() but always returns TRUE for empty vectors, even those that don't have a names attribute. In other words, it tests for the property that each element of a vector is named. is_named2() composes well with names2() whereas is_named() composes with names().

  • have_name() is a vectorised variant.

is_named(x)

is_named2(x)

have_name(x)

Arguments

x

A vector to test.

Value

is_named() and is_named2() are scalar predicates that return TRUE or FALSE. have_name() is vectorised and returns a logical vector as long as the input.

Details

is_named() always returns TRUE for empty vectors because

Examples

# is_named() is a scalar predicate about the whole vector of names: is_named(c(a = 1, b = 2))
#> [1] TRUE
is_named(c(a = 1, 2))
#> [1] FALSE
# Unlike is_named2(), is_named() returns `FALSE` for empty vectors # that don't have a `names` attribute. is_named(list())
#> [1] FALSE
is_named2(list())
#> [1] TRUE
# have_name() is a vectorised predicate have_name(c(a = 1, b = 2))
#> [1] TRUE TRUE
have_name(c(a = 1, 2))
#> [1] TRUE FALSE
# Empty and missing names are treated as invalid: invalid <- set_names(letters[1:5]) names(invalid)[1] <- "" names(invalid)[3] <- NA is_named(invalid)
#> [1] FALSE
have_name(invalid)
#> [1] FALSE TRUE FALSE TRUE TRUE
# A data frame normally has valid, unique names is_named(mtcars)
#> [1] TRUE
have_name(mtcars)
#> [1] 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)
#> [1] FALSE
names(mat)
#> NULL