perl return和break

zjzc01:/root/test# cat a3.pl 
sub mask {
        my $n=shift;
        my $j =100;
         for ($i = 1;$i <= 5;$i++){
         print "$i is $i
";
        while ($n=$n+1) {
                $j++;
          print "$n is $n
";
          if ($n==10){print "$n---end is $n
";$n=0;last};
        }}
};

&mask(1);
zjzc01:/root/test# perl a3.pl 
$i is 1
$n is 2
$n is 3
$n is 4
$n is 5
$n is 6
$n is 7
$n is 8
$n is 9
$n is 10
$n---end is 10
$i is 2
$n is 1
$n is 2
$n is 3
$n is 4
$n is 5
$n is 6
$n is 7
$n is 8
$n is 9
$n is 10
$n---end is 10
$i is 3
$n is 1
$n is 2
$n is 3
$n is 4
$n is 5
$n is 6
$n is 7
$n is 8
$n is 9
$n is 10
$n---end is 10
$i is 4
$n is 1
$n is 2
$n is 3
$n is 4
$n is 5
$n is 6
$n is 7
$n is 8
$n is 9
$n is 10
$n---end is 10
$i is 5
$n is 1
$n is 2
$n is 3
$n is 4
$n is 5
$n is 6
$n is 7
$n is 8
$n is 9
$n is 10
$n---end is 10


last 是退出当前循环

zjzc01:/root/test# cat a3.pl 
sub mask {
        my $n=shift;
        my $j =100;
         for ($i = 1;$i <= 5;$i++){
         print "$i is $i
";
        while ($n=$n+1) {
                $j++;
          print "$n is $n
";
          if ($n==10){print "$n---end is $n
";$n=0;return};
        }}
};

&mask(1);
zjzc01:/root/test# perl a3.pl 
$i is 1
$n is 2
$n is 3
$n is 4
$n is 5
$n is 6
$n is 7
$n is 8
$n is 9
$n is 10
$n---end is 10

return是退出当前函数

退出循环是break
return是退出函数并返回, 如果函数有返回值,可以将返回值返回