title: check if key exists in object in jquery
body: <p>I have a developed below code,</p>
  
  <pre><code>var list = [];
  // read data from api
  
  $.each(data.samples, function(k, v) {
    if (!list.hasOwnProperty(v.key) 
      list.push({
        'key': v.key,
        'title': v.title.
        'sent': false
      }); 
  
  console.log(list);
  </code></pre>
  
  <p>Updated(Sample Data From API)</p>
  
  <pre><code>var obj ={
      "expand": "schema,names",
      "startAt": 0,
      "maxResults": 50,
      "total": 4,
      "samples": [
          {
              "key": "s-111",
              "title": {
                  "summary": "title 1"
              }
          },
          {
              "key": "s-112",
              "title": {
                  "summary": "title 2"
              }
          },
          {
              "key": "s-113",
              "title": {
                  "summary": "title 3"
              }
          },
          {
              "key": "s-114",
              "title": {
                  "summary": "title 3"
              }
          }
      ]
  }
  </code></pre>
  
  <p>And some necessary nested key,value which i don't need it as well.
  however I just need to check if new key does not exists add new key to my list while API update every 2 minutes </p>