第十章：其他控制结构

1)
use warnings;
my $secretNum = int(1 + rand 1000);
my $num;
my $count = 0;
while(1){
 print "Please enter a number from 1 to 1000: ";
 chomp($num = <STDIN>);
 last if $num =~ /exit|quit|^\s*$/i;
 $count++;
 if ($num =~ /[\D]/){
  print "Number!!!\n";
  redo;
 }
 if ($num > 1000 or $num < 1){
  print "1..1000\n";
  redo;
 }
 if ($num < $secretNum){
  print "Too low! You have tried $count times.\n";
 } elsif ($num > $secretNum){
  print "Too high! You have tried $count times.\n";
 } else{  
  print "Bingo! You have tried $count times.\n";
  last;
 }
}