title: What is good practice for null reference checks?
body: <p>What is the most efficient way to check for null references on objects? I have seen various code samples that have different ways of checking so of the following which is the most efficient or the one that it is considered best practice to use?</p>
  
  <pre><code>Object.ReferenceEquals(item, null)
  
  item == null
  
  item != null
  
  Object.Equals(item, null)
  </code></pre>
  
  <p>thanks</p>