title: Ruby encode UTF-8 string to UTF-16
body: <p>I want to store the UTF-16 encoding into another variable as UTF-8 string.</p>
  
  <pre><code>1.9.3p194 :117 &gt; str = "سلام"
   =&gt; "سلام" 
  1.9.3p194 :118 &gt; enc = str.encode("utf-16")
   =&gt; "\uFEFF\u0633\u0644\u0627\u0645" 
  1.9.3p194 :119 &gt; puts enc
  ??3D'E
   =&gt; nil 
  </code></pre>
  
  <p>I want to store <code>\uFEFF\u0633\u0644\u0627\u0645</code> (not <code>??3D'E</code>) into a UTF-8 string so I can be able to concatenate it with other UTF-8 strings</p>