title: Using lodash filter I want to replace null with zero
body: <pre><code>let a = [{'abc': 1, 'qwe':2},{'abc': 2, 'qwe':2},{'abc': 5, 'qwe':null}, {'abc': 4, 'qwe':null}],
  
  let required =  _.chain(a)
                  _.groupBy(qwe)
                  _.map((value, key) =&gt; ({
                   name: key,
                   data: _.map(_.filter(value, item =&gt; {
                   return item.qwe;
  })
                    'qwe'
                   )
                 })).value()
                })
  </code></pre>
  <p>output is:</p>
  <blockquote>
  <p>qwe:[2,2,5]</p>
  </blockquote>
  <p>Expected output is:</p>
  <blockquote>
  <p>qwe:[2,2,5,0, 0]</p>
  </blockquote>