Re: A few random questions from Learning Perl 3

For the completeness of the "next" topic, we have to introduce the two brothers of "next": "last" and "redo".

next

The "next" statement allows you to jump to the next iteration of the loop without executing the remaining statements of the current iteration.
```
foreach (1..10) {
    next if ($_ == 9);
    print("$_  ");
}
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```
Here's what it looks like:

1 2 3 4 5 6 7 8 10

As you can see, 9 is missing - this is because when the value of $_ hits 9, Perl uses the "next" statement to skip to the next iteration of the loop, and so 9 never gets printed.
last

The "last" statement is used to exit the loop completely.
```
foreach (1..10) {
    last if ($_ == 9);
    print("$_  ");
}
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```
And here's the output:

1 2 3 4 5 6 7 8
redo

And finally, the redo statement lets you restart a particular iteration of the loop:
```
foreach (1..10) {
    print("$_  ");
    if ($_ == 9 && $flag != 1) {
        $flag=1;
        redo;
    }
}
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```
In this case, here's what you'll see:

1 2 3 4 5 6 7 8 9 9 10

Comment on Re: A few random questions from Learning Perl 3 Select or Download Code

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Re: Re: A few random questions from Learning Perl 3 by talexb (Chancellor) on Jan 06, 2003 at 14:39 UTC
Excellent answer, with one small adjustment to the last example to do with redo .. `my $flag = 0; foreach (1..10) { print("$_ "); if ($_ == 9 && $flag != 1) { $flag=1; redo; } }` [download] I have initialized flag to zero at the beginning of the loop. This was, of course, understood :) by all readers, but for the newcomer, it might be helpful. --t. alex Life is short: get busy!	[reply] [d/l]