title: Javascript: Multiple Filters in an Array
body: <p>I have an array of items that I'd like the user to be able to filter through in using multiple drop-down lists. In this case, each character for the strings has its own filter. </p>
  
  <p>My question is how can I filter my array once it's already been filtered?
  i.e. my array, parts, ["35X", "45X" "35L"], if I've already filtered down to strings containing '3', how can I filter down to strings containing 3 and L?</p>
  
  <pre><code>    var parts = [" 35X", " 35L", " X44", " 55L", " 55X"];
      var obj8 = document.getElementById("selectOperators");
      var obj1 = document.getElementById("Series");
  
  function getOption1() {
      var din = filterParts(obj1.options[obj1.selectedIndex].value)
      document.getElementById("other").innerHTML = din;
      }
  
  function getOption8() {
      var ryan = filterParts(obj8.options[obj8.selectedIndex].value)
      document.getElementById("other").innerHTML = ryan;
      }
  
  function filterParts(query) {
      return parts.filter((el) =&gt; el.toLowerCase().indexOf(query.toLowerCase()) &gt; -1)
      } 
  </code></pre>
  
  <p>If possible to do so without the use of jquery</p>