The following code will NOT work:
my @array = (5, 4, 3, 2, 1);

foreach (0 .. $#array) {
    print "$_ => $array[$_]\n";
    if ($array[$_] <= 3) {
        print "Splicing $_ => $array[$_]\n";
        splice @array, $_, 1;
    }
}

[download]

What happens is that (0 .. $#array) is set to (0 .. 4) at the very beginning of the list. This means that you'll be trying to access an array subscript that doesn't exist if any of your splices actually occur.

This is actually one of the few places that a while loop is better than a foreach loop. Make the following change:

my @array = (5, 4, 3, 2, 1);

my $i = 0;
SPLICER:
while ($i < @array) {
    print "$i => $array[$i]\n";
    if ($array[$i] <= 3) {
        print "Splicing $i => $array[$i]\n";
        splice @array, $i, 1;
        next SPLICER;
    }
    $i++;
}

[download]
That works quite nicely.

In reply to Re: removing x from a list by satchboost
in thread removing x from a list by ashaman

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.