[R] Is a string all blanks?

[David Winsemius]

On Aug 2, 2011, at 8:07 PM, John Sorkin wrote:

> windows 7
> R 2.12.1
>
> Is there any easy way to determine if a sting contains nothing but  
> blanks? I need to check a series of strings of various length.
>
> OneBlank <- " "
> TwoBlanks <- "  "
> ThreeBlanks <- "   "
> NoBlanks <- "NoBlanks"
>
> What I want would be a function such as ALLBLANKS that would return  
> the following
> ALLBLANKS(OneBlank) would be true (or 1)
> ALLBLANKS(TwoBlanks) would be true (or 1)
> ALLBLANKS(ThreeBlanks) would be true (or 1)
> ALLBLANKS(NoBlanks) would be false (or 0)

 > bvec <- c(OneBlank, TwoBlanks ,ThreeBlanks ,NoBlanks)
 > grepl(" +", bvec)
[1]  TRUE  TRUE  TRUE FALSE

-- 
David Winsemius, MD
West Hartford, CT