title: swift: how can I delete a specific character?
body: <p>a string such as <code>!   !! yuahl! !</code> , I want delete <code>!</code> and  <code></code>, when I code like this </p>
  
  <pre><code>for index in InputName.characters.indices {
      if String(InputName[index]) == "" || InputName.substringToIndex(index) == "!" {
          InputName.removeAtIndex(index)
      }
  }
  </code></pre>
  
  <p>have this error " fatal error: subscript: subRange extends past String end ", how should I do? THX :D </p>