Here's a solution using an array slice.

#!/usr/bin/env perl

use 5.010;
use strict;
use warnings;

use List::Util qw{shuffle};

my $array_elements = 60;    # originally 600
my $random_elements = 3;    # originally 10
my $no_of_arrays = 10;      # originally 1000
my $norm_char = q{-};
my $rand_char = q{X};

my @all_strings = ();

for (1 .. $no_of_arrays) {
    my @tmp_array = ($norm_char) x $array_elements;

    @tmp_array[(shuffle 0 .. $array_elements - 1)[0 .. $random_element
+s - 1]]
        = ($rand_char) x $random_elements;

    push @all_strings => join q{} => @tmp_array;
}

map { say } @all_strings;
[download]

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.