[R] How to deal with character(0)?

[Duncan Murdoch]

On 11/15/2007 4:54 PM, Gang Chen wrote:
> I want to identify whether a variable is character(0), but get lost.  
> For example, if I have
> 
>  > dd<-character(0)
> 
> the following doesn't seem to serve as a good identifier:
> 
>  > dd==character(0)
> logical(0)
> 
> So how to detect character(0)?

(length(dd) == 0) && (typeof(dd) == "character")

or if you really want to be specific (and rule out things that just act 
like character(0) in most respects)

identical(dd, character(0))

Duncan Murdoch