title: Remove array of objects from another array of objects
body: <p>Assume we have the following arrays of objects to be compared based on property <code>id</code>:</p>
  
  <pre><code>a = [{'id':'1', 'name':'a1'}, {'id':'2', 'name':'a2'}, {'id':'3', 'name':'a3'}]
  </code></pre>
  
  <p>and</p>
  
  <pre><code>b = [[{'id':'2', 'name':'a2'}, ]
  </code></pre>
  
  <p>How can I subtract b from a? So that we have <code>c = a - b</code> which should be equal to <code>[ {'id':'1', 'name':'a1'}, {'id':'3', 'name':'a3'}]</code>.</p>
  
  <p>I have tried using this:</p>
  
  <pre><code>var c= a.filter(function(item) {
                      return !b.includes(item.id);
                  });
  </code></pre>
  
  <p>but still not working.</p>