PHP: How to print associative array using while loop?

I have a simple associative array.

<?php
$assocArray = array('a' => 1, 'b' => 2, 'c' => 3);
?>

Using only while loop, how can I print it in this result?

$a = 1 
$b = 2 
$c = 3

This is my current solution but I think that this is not the efficient/best way to do it?

<?php
$assocArray = array('a' => 1, 'b' => 2, 'c' => 3);
$keys = array_keys($assocArray);
rsort($keys);

while (!empty($keys)) {
    $key = array_pop($keys);
    echo $key . ' = ' . $assocArray[$key] . '<br />';
};
?>

Thanks.