title: React native - Change styles dynamically
body: <p>I have a dynamic menu that I created using a map method.</p>
  <pre><code>          {navigationOptions.map(option =&gt; {
                return (
                  &lt;TouchableOpacity key={option.code}
                    onPress={() =&gt; this.procedureOptionSelected(option.code)}
                  &gt;
                    &lt;Text bold style={header.NavigationBarOption}&gt;
                      {option.type}
                    &lt;/Text&gt;
                  &lt;/TouchableOpacity&gt;
                );
              })}
  </code></pre>
  <p>However, I need an underline when I press a menu option.</p>
  <p>So let's assume, that I pressed the first option. So, in the first option, there must be an underscore.</p>
  <p>But I don't know how to do this in react native.
  Could someone help me with an idea?</p>
  <p>Thanks!</p>