title: in c# how to convert an var to a char array. char array[8]
body: <p>in c# how to convert an varto a char array. char[8] array
  I can guarantee this var is not too big.</p>
  
  <p>such as, I have </p>
  
  <pre><code>var a = 634711440648369988;
  </code></pre>
  
  <p>and I want <code>char[8] c</code> store it.</p>
  
  <p>How to do this conversion correctly?
  Thanks.</p>