title: jQuery: If key exists in array, get value
body: <p>I am trying to see if a certain key exists in an array, and if so, return it's value:</p>
  
  <pre><code>if(jQuery.inArray(live_ids.grade, item.SizePrice) !== -1) {
  
      console.log(item.SizePrice);
  
  }
  </code></pre>
  
  <p>This will return:</p>
  
  <pre><code>{"8":"15.00","7":"20.00","1":"6.00","6":"11.00","2":"7.00","3":"8.00","4":"9.00","5":"10.00","11":"20.00","9":"10.00","10":"15.00","13":""}
  </code></pre>
  
  <p>Now, <code>live_ids.grade</code> = 9, so I want to be able to return <code>10.00</code>... how do I do that?</p>