$code = soundex $string; # get soundex code for a string @codes = soundex @list; # get list of codes for list of strings
# set value to be returned for strings without soundex code
$soundex_nocode = 'Z000';
If there is no soundex code representation for a string then the value of $soundex_nocode is returned. This is initially set to "undef", but many people seem to prefer an unlikely value like "Z000" (how unlikely this is depends on the data set being dealt with.) Any value can be assigned to $soundex_nocode.
In scalar context "soundex" returns the soundex code of its first argument, and in list context a list is returned in which each element is the soundex code for the corresponding argument passed to "soundex" e.g.
@codes = soundex qw(Mike Stok);
leaves @codes containing "('M200', 'S320')".
Euler, Ellery -> E460 Gauss, Ghosh -> G200 Hilbert, Heilbronn -> H416 Knuth, Kant -> K530 Lloyd, Ladd -> L300 Lukasiewicz, Lissajous -> L222
$code = soundex 'Knuth'; # $code contains 'K530' @list = soundex qw(Lloyd Gauss); # @list contains 'L300', 'G200'
As it is mapping a large space (arbitrary length strings) onto a small space (single letter plus 3 digits) no inference can be made about the similarity of two strings which end up with the same soundex code. For example, both "Hilbert" and "Heilbronn" end up with a soundex code of "H416".