break a word in letters php
<p>I want to accept a string from a form and then break it into an array of characters using PHP, for example:</p>

<pre><code>$a = 'professor';
$b[0] == 'p';
$b[1] == 'r';
$b[2] == 'o';
.
.
.
.
.
$b[8] = 'r';
</code></pre>
