title: Dart: How to combine Two Arrays based on ID?
body: <p>I have a list like below:</p>
  <pre><code>var list1=[
        {&quot;id&quot;: &quot;10&quot;, &quot;name&quot;: &quot;item1&quot;},
        {&quot;id&quot;: &quot;20&quot;, &quot;name&quot;: &quot;item2&quot;},
        {&quot;id&quot;: &quot;30&quot;, &quot;name&quot;: &quot;item3&quot;},
        {&quot;id&quot;: &quot;40&quot;, &quot;name&quot;: &quot;item4&quot;}];
  
  var list2=[
        {&quot;id&quot;: &quot;10&quot;, &quot;qty&quot;: 20},
        {&quot;id&quot;: &quot;20&quot;, &quot;qty&quot;: 12},     
        {&quot;id&quot;: &quot;40&quot;, &quot;qty&quot;: 10}];
  </code></pre>
  <p>I want a new list like:</p>
  <pre><code>List&lt;Map&lt;String,dynamic&gt;&gt; list3= [
            {&quot;id&quot;: &quot;10&quot;, &quot;name&quot;: &quot;item1&quot;,&quot;qty&quot;: 20},
            {&quot;id&quot;: &quot;20&quot;, &quot;name&quot;: &quot;item2&quot;,&quot;qty&quot;: 12},
            {&quot;id&quot;: &quot;30&quot;, &quot;name&quot;: &quot;item3&quot;,&quot;qty&quot;: 0},
            {&quot;id&quot;: &quot;40&quot;, &quot;name&quot;: &quot;item4&quot;,&quot;qty&quot;: 10}];
  </code></pre>
  <p>How to do this? Need help...</p>