我如何对数组进行升序而不是随机排序

I found this awesome snippet online. It shows a new testimonial at random on refresh of the page and am wondering how to show the array in an ascending order rather than random?

$target = sort(0, $num-1); 

^ This was my attempt

<?php
    /*
    --------------------------------------------
    Random Testimonial Generator Created by:
    Ryan McCormick
    Ntech Communications
    Website: http://www.ntechcomm.com/
    Blog: http://www.ntechcomm.com/blog/
    Twitter: @ntechcomm
    --------------------------------------------
    */

    //Start Array
    $testimonials = array();
    $testimonials[0] = "Testimonial 1";
    $testimonials[1] = "Testimonial 2";
    $testimonials[2] = "Testimonial 3";
    $testimonials[3] = "Testimonial 4";
    //Automate script by counting all testimonials
    $num = count($testimonials);
    //randomize target testimonial
    $target = rand(0, $num-1);
    /*
    To display testimonials on site
    --------------------------------------------
    place the following code in the
    display area:
    <?php echo $testimonials[$target]; ?>
    --------------------------------------------
    Use a PHP include to use this code on your
    target page.
    */
    ?>

Output the testimonial in page with:

<?php echo $testimonials[$target]; ?>

To clarify:

The code i posted displays one testimonial randomly on refresh of the page. I would like it to keep this function and display only one at a time but I want them to display in the order they are added.

Sort using ascending order

$testimonials = array();
$testimonials[0] = "Testimonial 1";
$testimonials[1] = "Testimonial 2";
$testimonials[2] = "Testimonial 3";
$testimonials[3] = "Testimonial 4";

$random  = rand(0, count($testimonials) - 1);
$asc_arr = sort($testimonials);
print_r($result);

You can use sort() to sort an array's values in ascending order. Here's the documentation for it.

http://php.net/manual/en/function.sort.php

Basically, you can use it like this:

$myarray = array('aa', 'bb', 'abc', 'cde', 'az');
sort($myarray);
var_dump($myarray);

In addition (because of the "The code i posted displays one testimonial randomly on refresh of the page. I would like it to keep this function and display only one at a time but show the testimonials ascending in order" clarification added by OP):

If you want to display just one testimonial per page load, then you'll need to retain the last array index on each page load. If it's just whenever the page is refreshed, then you can use a session variable. Something like this:

session_start();
if (!isset($_SESSION['cur_index'])) { $_SESSION['cur_index'] = 0; }
$target = $_SESSION['cur_index'];
// Prepare for the next index when the page is refreshed.
$_SESSION['cur_index']++;
// If the index goes pass the array's limit, then go back to index 0.
if ($_SESSION['cur_index'] >= count($testimonials)) {
    $_SESSION['cur_index'] = 0;
}

That will update the $target variable to the next index based off of the previous index.