title: Dart: What do these square brackets do in the constructor?
body: <pre><code>  Minesweeper([List&lt;String&gt; _input]){
      //...
    }
  </code></pre>
  
  <p>I've checked the <a href="https://dart.dev/guides/language/language-tour" rel="noreferrer">Dart</a>'s official documentation in the sections "classes" and "lists" but neither seem to have a reference to such a syntax. I guess it's a "direct initializer"(?) so the _input field is filled without writing it explicitly in the constructor?</p>