title: array_map and trim not trimming white space from values
body: <p>This function below returns a string of values comma separated</p>
  
  <p><code>$key_1_value = get_post_meta(422,'keywords',true);</code></p>
  
  <p>The output in my browser looks like
  <code>red, white, blue, blue two  , green, yellow, purple, magenta                                                                                                             , cyan, black</code></p>
  
  <p>I'm trying to trim the white space before and after all values.</p>
  
  <p>So I used this code to try and trim the whitespace but it's still there. Why won't this trim the values?</p>
  
  <pre><code>$test = array($key_1_value);
  $trimmed_array=array_map('trim',$test);
  print_r($trimmed_array);
  </code></pre>