title: How do I handle a List of Lists?
body: <p>Could someone explain what goes wrong in this piece of code?
  From the code one (at least myself) would expect that after having ran this code the number list would look like <code>numbers = [[0], [1]]</code>, but instead it looks like <code>numbers= [[0,1], [0,1]]</code>.</p>
  
  <pre class="lang-dart prettyprint-override"><code>void main() {
    int n = 2;
    List&lt;List&lt;int&gt;&gt; numbers = new List.filled(n, []);
    
    for(int i=0; i&lt;n; i++)
      for(int j=i+1; j&lt;n; j++ ){
        numbers[i].add(0);
        numbers[j].add(1);
      }
  }
  </code></pre>