title: How find variable/array if I don't know full variable name in javascript
body: <p>I am trying to get additional information from site and there is variable/array that defined randomly. Like this:</p>
  
  <pre><code>var firstvar_numbers= "already exist"
  var secondvar_numbers= ["a","b","c","d"]
  
  </code></pre>
  
  <p>numbers is random value that given by site. In firefox DOM when I wrote half of <code>secondvar_</code> it immediately find that I wanted because there is only one variable that starts with <code>second</code>. My question is how I can get value/array of variable in userscript/javascript by knowing part of the variable.
  Example if you don't understood:
  Html</p>
  
  <pre><code>//Variable that I need from server
  &lt;div id="variables" class="container"&gt;
  
  &lt;script type="text/javascript"&gt;
  var exists_73647286="hello world"
  
  var array_636353=[62,96,11,28]
  &lt;/script&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Javascript</p>
  
  <pre><code>//Code that will get array
  alert("exists_"+seconpartofvar())
  function seconpartofvar(){your code}
  
  </code></pre>
  
  <p>OR</p>
  
  <pre><code>alert(autocomplate.exists_)
  </code></pre>
  
  <p>Here I can write <code>alert(exists_)</code> in Firefox console and it will recommend autocomplate.</p>