title: Correct way to initialize a complex array to zero
body: <p>What would be a quick and accurate way of initializing a complex array? Are there any differences in the following:</p>
  
  <pre><code>complex(real64) :: x(2,2)
  x = 0
  x = 0d0
  x = (0d0,0d0)
  </code></pre>
  
  <p>Are they the same and can I assume I get the same result on every compiler? Does the standard say anything about it? The question is <em>specifically</em> about initializing to zero, not any other number.</p>