title: Is all javascript object reference type?
body: <p>All, Say we have the code like below.</p>
  
  <pre><code>var b ={};
  
  var a=b;
  b=null;
  if (a==null)
  {
      alert('a is null');
  }
  </code></pre>
  
  <p>Before the code running, I had thought the <code>a</code> should be null, because I thought <code>a</code> and <code>b</code> are pointing to same object or they are supposed to be the same address. but it is not . Isn't javascript object reference type like classical language (c++/c#/java)? Or did I miss something important? Thanks.</p>