title: Check single element into ArrayList with multiple column
body: <p>I have an ArrayList:</p>
  
  <pre><code>ArrayList &lt;Elem&gt; list=new ArrayList &lt;Elem&gt;();
  </code></pre>
  
  <p>where </p>
  
  <pre><code>class Elem{
  public String name;
  public int a;
  public int b;
  } 
  </code></pre>
  
  <p>I add several different objects into this ArrayList where each object contains 3 elements - String, int, int.</p>
  
  <p>Now I would like know if a Name, given in input, is already in the ArrayList.
  How I can do?
  Thanks in advance.</p>