title: change value to other value and the "!" operator
body: <p>so by the logic in my head:</p>
  
  <p>if I touch the opacity of Email then globlas.Email should change from false to true but in fact it does nothing</p>
  
  <p>because I think when 'this.getMedia(item.MediaNow)' = true
  then musst be:   '!(!this.getMedia(item.MediaNow))' = false</p>
  
  <p>could someone please explain me why?
  or maybe tel me how to make my code work like I intend.</p>
  
  <pre><code>getMedia = Media =&gt; {
   switch (Media) {
     case "Call":
      return global.Call;
    case "Email":
      return global.Email;
  
  
  setMedia = (Media, value) =&gt; {
   switch (Media) {
    case "Call":
      global.Call = value;
      this.setState({});
  
    case "Email":
      global.Email= value;
      this.setState({});
  
  
   {...}
  
  
   &lt;TouchableOpacity
    onPress={() =&gt; {
     this.setMedia(!this.getMedia(item.MediaNow)); 
  // MediaNow is either "Call" or "Email". so my expectet result of 
  // (!this.getMedia(item.MediaNow)) would be: true/false
  
    }}
   &gt;
  </code></pre>
  
  <h3>global.js:</h3>
  
  <pre><code>export default {
   Call: false,
   Email: false,
  };
  </code></pre>
  
  <h3>Thanks a lot in advance</h3>