is_empty() checks is an object is empty (any zero-length dimensions).
has_length() checks how long is an object.
has_names() checks if an object is named.
has_duplicates() checks if an object has duplicated elements.
has_missing() and has_infinite() check if an object contains missing
or infinite values.
has_length(x, n = NULL)has_names(x, names = NULL)
has_duplicates(x)
has_missing(x)
has_infinite(x)
is_empty(x)
is_unique(x, na.rm = FALSE)
A logical scalar.
A vector to be tested.
A length-one numeric vector specifying the length to test x
with. If NULL, returns TRUE if x has length greater than zero, and
FALSE otherwise.
A character vector specifying the names to test x
with. If NULL, returns TRUE if x has names, and FALSE otherwise.
A logical scalar: should missing values (including NaN)
be omitted?
Other predicates:
predicate-matrix,
predicate-numeric,
predicate-scalar,
predicate-trend,
predicate-type