title: What does the empty parentheses after the onPressed property mean in Dart?
body: <p>I know the syntax for calling a function after <code>onPressed</code> and <code>onTap</code> for a widget. There are two options We can use either the <code>() =&gt; function()</code> or the <code>() { function(); }</code> syntax. What do the empty parentheses mean?</p>