I'm not fond of this kind of magic...

# this works
#!/usr/bin/perl -w   
use strict;
my $a = "a";
print ++$a ."\n";
print ++$a ."\n";
print ++$a ."\n";

# this also works
#!/usr/bin/perl -w   
use strict;
my $a = "a8";
print ++$a ."\n";
print ++$a ."\n";
print ++$a ."\n";

# but this is unpredictable
#!/usr/bin/perl -w   
use strict;
my $a = "a8y";
print ++$a ."\n";
print ++$a ."\n";
print ++$a ."\n";
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update Or better as posted by sh1tn: see the difference

perl -e '$char = "a"; print $char++, $/ for 1..20'
perl -e '$char = "a0"; print $char++, $/ for 1..20'
perl -e '$char = "a0a"; print $char++, $/ for 1..20'
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