-------------------------------------------------------------------------------
help for charlist
-------------------------------------------------------------------------------

List characters present in string variable

        charlist strvar [if exp] [in range]


Description

    charlist displays a sorted list of the distinct characters present in
    values of string variable strvar.


Remarks

    charlist may, for example, reveal the presence of problematic characters
    in a string variable which "should be" numeric.  It leaves behind a terse
    character list in r(chars); a space-separated character list in
    r(sepchars); and a space-separated numlist of ASCII codes in r(ascii).
    Any may be used in a subsequent command. Sometimes copying and pasting
    all or part of the displayed output to the command window may be the most
    practical way to use the output, say as argument to destring, ignore().

    Note in particular that many awkward characters may not print
    comprehensibly or visibly in your Results window. To some extent, this
    will depend on the font you choose. A particular pitfall is that char(32)
    and char(160) appear identical and may be overlooked in any case. The
    returned results showing ASCII codes are needed to solve many of these
    difficulties.


Examples

    . charlist make

    . charlist make if foreign

    . charlist rank
    . return list
    [suppose results show instances of char(160)]
    . destring rank, ignore(`=char(160)')

   
Saved results 

    r(chars)            compressed list of distinct characters
    r(sepchars)         space-separated list of distinct characters
    r(ascii)            numeric list of distinct ASCII codes (cf. char())


Acknowledgements 

    Daniel Egan posed a problem that led to extra comments and examples in
    this help file.


Author 

    Nicholas J. Cox, Durham University, U.K.
    n.j.cox@durham.ac.uk

         
Also see

    On-line:  help for destring, functions