he sum of an iterable:</p>
<pre class="language-dart"><code>iterable.reduce((value, element) =&gt; value + element);
</code></pre>
    </section>
    
    <section class="summary source-code" id="source">
      <h2><span>Implementation</span></h2>
      <pre class="language-dart"><code class="language-dart">E reduce(E combine(E previousValue, E element)) {
  int length = this.length;
  if (length == 0) throw IterableElementError.noElement();
  E value = this[0];
  for (int i = 1; i &lt; length; i++) {
    v