title: How would I catch and deal with "undefined" from parsed json object
body: <p>I'm trying to populate a spreadsheet from a RESTful service and sometimes there's no such property so I get an "undefined" in my spreadsheet and the script stops and gives an error. I have no clue as to how to go about dealing with it, or skipping over the "undefined" part.</p>
  
  <p>Here's a sample query in json</p>
  
  <p>{</p>
  
  <pre><code>"rel": "self",
  "url": "https://www.sciencebase.gov/catalog/items?max=2&amp;s=Search&amp;q=project+
  2009+WLCI&amp;format=json&amp;fields=title%2Csummary%2Cspatial%2Cfacets",
  "total": 65,
  "nextlink": {
      "rel": "next",
      "url": "https://www.sciencebase.gov/catalog/items?max=2&amp;s=
  Search&amp;q=project+2009+WLCI&amp;format=json&amp;fields=title%2Csummary%2
  Cspatial%2Cfacets&amp;offset=2"
  },
  "items": [
      {
          "link": {
              "rel": "self",
              "url": "https://www.sciencebase.gov/catalog/item/
               4f4e4ac3e4b07f02db67875f"
          },
          "id": "4f4e4ac3e4b07f02db67875f",
          "title": "Decision-Making and Evaluation - Social and Economic 
          Evaluation Supporting Adaptive Management for WLCI",
          "summary": "Provide information on the social and economic environment 
          for the WLCI area and provide context for the biological and physical 
          aspects of this project.",
          "spatial": {
              "representationalPoint": [
                  -108.585,
                  42.141
              ]
          },
          "facets": [
              {
                  "startDate": "2007-10-01 00:00:00",
                  "projectStatus": "Active",
                  "facetName": "Project",
                  "_class": "ProjectFacet",
                  "active": true,
                  "className": "gov.sciencebase.catalog.item.facet.ProjectFacet",
                  "endDate": null,
                  "projectType": "Science",
                  "_embeddedClassName": "gov.sciencebase.catalog.item.facet.
                  ProjectFacet"
              }
          ]
      },
      {
          "link": {
              "rel": "self",
              "url": "https://www.sciencebase.gov/catalog/item
              /4f4e4ac0e4b07f02db676d57"
          },
          "id": "4f4e4ac0e4b07f02db676d57",
          "title": "Data and Information Management Products for the Wyoming 
          Landscape Conservation Initiative"
      }
  ]
  </code></pre>
  
  <p>}</p>
  
  <p>Since the second item has only a title and nothing more after that I get "undefined" if I try to get a summary or facet etc. for items using a loop. I've thought of and tried using if statements like </p>
  
  <pre><code>if (parsedResponse.items[i].summary === "undefined") {
      Do something here;
  }
  </code></pre>
  
  <p>but this doesn't seem to work. Any suggestions I could try are appreciated. Thanks</p>