title: How to replace all special character into a string using C#
body: <p>I would like to replace all special characters in a string with a <code>comma (,)</code>.</p>
  
  <p>For Example: </p>
  
  <pre><code>Hello@Hello&amp;Hello(Hello)
  </code></pre>
  
  <p>the output - </p>
  
  <pre><code>Hello,Hello,Hello,Hello,
  </code></pre>
  
  <p>(I don't known how to use regexp in C#) </p>
  
  <p>Can i do this work using regexp in C#?</p>