title: ArrayList objects
body: <p>Need some inputs:</p>
  
  <p>Lets say i have N <code>ArrayList</code> and in each i am adding foo() object.</p>
  
  <pre><code>Foo foo = new Foo()
  
  A.add(foo);
  
  B.add(foo);
  
  N.add(foo);
  </code></pre>
  
  <p>Now modification done on any one <code>foo()</code> object will reflect in all the other arraylist?</p>
  
  <ol>
  <li><p>If YES WHY? and </p></li>
  <li><p>whether this behaviour can also be achieved using any other collection like Vector etc...?</p></li>
  <li><p>IF i make foo as null will it reflect in all arraylist?</p></li>
  </ol>