#!/usr/bin/perl $S = "a , b, c,d"; sub modif { my ($S) = @_; $S =~ s/(.*),/$1 and /; $S =~ s/\s*,\s*/, /g; return $S; } print "\$S=$S ==> ". modif($S) . "\n"; #### @Arr = (1 , 2, 3,4); print "Array = ". modif(join(',',@Arr)) . "\n";