while 退出循环

[oracle@oadb tmp]$ cat a1.pl 
$i=1;
while (1==1){
$i++;

print "1----------$i is $i
";
if ($i == 7){print "2-------$i is $i
";last;}
print "${i}xxxxxxxxxxxxxx${i}
";
};


[oracle@oadb tmp]$ perl a1.pl 
1----------$i is 2
2xxxxxxxxxxxxxx2
1----------$i is 3
3xxxxxxxxxxxxxx3
1----------$i is 4
4xxxxxxxxxxxxxx4
1----------$i is 5
5xxxxxxxxxxxxxx5
1----------$i is 6
6xxxxxxxxxxxxxx6
1----------$i is 7
2-------$i is 7

last 退出当前循环:

[oracle@oadb tmp]$ cat a2.pl 
while (1==1){
$j=$j+5;
print "$j===$j
";
$i=1;
while (1==1){
$i++;

print "1----------$i is $i
";
if ($i == 7){print "2-------$i is $i
";last;}
print "${i}xxxxxxxxxxxxxx${i}
";
};
sleep 5;
};

[oracle@oadb tmp]$ perl a2.pl 
$j===5
1----------$i is 2
2xxxxxxxxxxxxxx2
1----------$i is 3
3xxxxxxxxxxxxxx3
1----------$i is 4
4xxxxxxxxxxxxxx4
1----------$i is 5
5xxxxxxxxxxxxxx5
1----------$i is 6
6xxxxxxxxxxxxxx6
1----------$i is 7
2-------$i is 7
$j===10
1----------$i is 2
2xxxxxxxxxxxxxx2
1----------$i is 3
3xxxxxxxxxxxxxx3
1----------$i is 4
4xxxxxxxxxxxxxx4
1----------$i is 5
5xxxxxxxxxxxxxx5
1----------$i is 6
6xxxxxxxxxxxxxx6
1----------$i is 7
2-------$i is 7