Way too hackish, not to mention it breaks if the chosen delimiter appears in your input strings - I'll get back to that in a bit though.

To find the common prefix, you have to iterate over two variables; be that scalars or arrays. Using a for loop:

my (@str1, @str2);

my ($i, @prefix) = (0);
for(@str1) {
    last if $_ ne $str2[$i++];
    push @prefix, $_;
}

[download]
Or a while loop: 
my (@str1, @str2);

my ($i, @prefix) = (0);

push @prefix, $str1[$i++] while($str1[$i] eq $str2[$i]);

[download]
I'd definitely prefer the while version, simply because the arrays are treated equally. Now let's look at how you'd do that over scalars: 
my ($s1, $s2) = ("ABCD", "ABEF");

my $i = 0;
$i++ while substr($s1, $i, 1) eq substr($s2, $i, 1);

my $prefix = substr $s1, 0, $i;

[download]

That's hardly any different to read, way clearer than the regex solution, shorter and more idiomatic to boot, and doesn't break regardless of input. Ok, using the ternary operator for your code would shorten the regex approach, but if anything, it would probably conceil the code's intent even further.

No, the only advantage strings-as-arrays would offer as far as I can see is for simulatenously replacing multiple non-contiguous parts of the string with parts of some other string. But then, that's such a rare circumstance that it shouldn't be unacceptably painful to just listify the strings using /(.)/sg for that, then glue the result back together.

I do see compelling reasons to syntactically extend push, shift and friends for dealing with strings (although I also see reasons not to), but definitely not for making strings fullblown arrays.

Makeshifts last the longest.

In reply to Re^3: Are strings lists of characters? by Aristotle
in thread Are strings lists of characters? by John M. Dlugosz

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.