title: LinkedList temp.next and temp?
body: <p>So I was practicing some linked list problems and I keep getting mixed up with let say we do 
  // this is a head only singly linked list</p>
  
  <pre><code>// what is the difference between 
  
  ListNode temp = head;
  while( temp != null ) {
      temp = temp.next ; 
  } 
  
  while( temp.next != null ) {
      temp = temp.next ; 
  } 
  </code></pre>
  
  <p>again what is the difference between the two ? If you can please explain to me this it would be greatly appreciated. </p>