Be careful using splice during array iteration.

Note the subtle bug here: 

my @items = ( 0..5 );
my $index = 0;
for my $value (@items) {
  print "testing $value\n";
  if ( $value == 1 or $value == 3 ) {
    print "removed value $value\n";
    splice @items, $index, 1;
  }
  $index++;
}

[download]

Values 2 and 4 are never actually tested for; iteration skips them completely!

If you want to iterate over an array removing some items, try something like: 

my $index = 0;
while ($index <= $#items ) {
  my $value = $items[$index];
  print "testing $value\n";
  if ( $value == 1 or $value == 3 ) {
    print "removed value $value\n";
    splice @items, $index, 1;
  } else {
    $index++;
  }
}

[download]

And, this being Perl I bet there are many other safe iteration/splice approaches... 8-)

In reply to Re: How do I completely remove an element from an array? by jaa
in thread How do I completely remove an element from an array? by vroom

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