title: JMeter JSON Extractor, extract all values of one key in a string
body: <p>Using Apache JMeter ver 3.2 r1790745 (the latest) to test a JSON Web Service, the response is like:</p>
  
  <pre><code>[ {
     "id" : 3,
     "description" : "Back",
     "name" : "back"
  }, {
     "id" : 1,
     "description" : "Front",
     "name" : "front"
  }, {
     "id" : 6,
     "description" : "Left",
     "name" : "left"
  }]
  </code></pre>
  
  <p>Want to parse the above response to get all ids in one string in JSON Extractor, like</p>
  
  <pre><code>3,1,6
  </code></pre>
  
  <p>My JSON Path expressions is like this:</p>
  
  <pre><code>$..id
  </code></pre>
  
  <p>But I got only the 1st id which is 3, the same result as <code>$.[0].id</code>
  Checking the result in a BeanShell PostProcessor.
  If I go to <a href="http://jsonpath.com/" rel="nofollow noreferrer">http://jsonpath.com/</a>
  $..id does give me </p>
  
  <pre><code>[
    3,
    1,
    6
  ]
  </code></pre>