title: Assigning the variable name to the same variable name
body: <p>On executing</p>
  
  <pre><code>var a=b=c=d=e=f=a; 
  //no error(a has not initialize before)
  
  var x=y;
  //ReferenceError: y is not defined
  </code></pre>
  
  <p>How can the first code just execute as if <code>a</code> has already been initialize before.</p>