I was talking to a friend about foreach aliasing the loop variable one by one through the list provided... As he was playing around with it, came across this:

  use Data::Dumper;
  @headers = ("header 1","header 2","header 3");
  @body = ("body A","body B","body C");
  $h = 4;
  foreach (@headers,"",@body) {
        print "$h: $_\n";
            @body = ();
                push @headers,"header ".$h++;
  }
  print "\n", scalar @headers, "\n", Dumper \@headers;

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Which produces: 
  4: header 1
  5: header 2
  6: header 3
  7:
  8: header 4
  9: header 5
  10: header 6

  10
  $VAR1 = [
            'header 1',
            'header 2',
            'header 3',
            'header 4',
            'header 5',
            'header 6',
            'header 7',
            'header 8',
            'header 9',
            'header 10'
          ];

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And I say huh? I follow until output line "7:". I can even see why it would run 3 more times (since the list fed to foreach was evaluated before @body was modified).

What I don't get is how the next 3 elements of @headers get in there? Is this part of the "don't mess with the loop vars while looping" clause?

What am I missing?

-- zigdon

In reply to Mutable foreach list? by zigdon

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