zjzc01:/root/test# cat a3.pl

sub mask {

        my $n=shift;

        my $j =100;

         for ($i = 1;$i <= 5;$i++){

         print "\$i is $i\n";

        while ($n=$n+1) {

                $j++;

          print "\$n is $n\n";

          if ($n==10){print "\$n---end is $n\n";$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\n";

        while ($n=$n+1) {

                $j++;

          print "\$n is $n\n";

          if ($n==10){print "\$n---end is $n\n";$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