title: How to flatten an array to a string of the values?
body: <p>I have an array that looks like this. </p>
  
  <pre><code>'keyvals' =&gt; 
      array
        'key1' =&gt; 'value1'
        'key2' =&gt; 'value2'
        'key3' =&gt; 'value3'
  </code></pre>
  
  <p>Is there a cool way to flatten it to a string like <code>'value1 value2 value3'</code>? I also have access to PHP 5.3 if there's something new there.</p>