title: How do I convert NSString to const void
body: <p>I am currently having issues converting <code>NSString</code> to a <code>const void *</code></p>
  
  <p>Here is my code:</p>
  
  <pre><code>DoSomethingFunction:(const void *)parameter
  
   [class DoSomeThingFunction:(const void *)passswordField.text]
  </code></pre>
  
  <p>Password field is a <code>UITextfield</code>. The value becomes null when I try and cast it.</p>
  
  <p>I want <code>passwordField.text</code> to be a <code>const void *</code> so it can be used in the function.</p>