returns a vector of the column names of the object data.
Details
The function returns the names slot of the object.
You can use it on the left side of an assignment to replace the names vector
with a new value. In that case, the replacement value is coerced to
class character using as. Replacing the
names with a vector of a different length causes
the classes and columns slots of object
to be extended or truncated to the new length. (The default class
is numeric for the extension.)