yours is good, but why chomp? no need with that regexp...

print "** Random 4 Lotto Numbers **\n";
print "** Type any four digits (0 to 9) **\n";

for ($i=1; $i <= 4; $i++) {
     print "Choice $i: ";
     redo if ($digit[$i] = <STDIN>) !~ /^\d$/;
}
   
print "Your choices :@digit \n";
[download]

since the $ works fine with \n there
                - Ant