title: using Float numbers for the map's key
body: <p>after I create a new object : <code>Map&lt;Float,Integer&gt; m = new HashMap()&lt;Float,Integer&gt;;</code></p>
  
  <p>I have an array with <code>"float"</code> numbers which are unique . I want to add these float numbers as the <code>m's key</code>! can I do this like :  <code>m.put(new Float(a[i]),"cat");</code>   ?</p>
  
  <p>thanks</p>