title: Realm JS : querying a string inside a list of string (Mongo equivalent to elemMatch)
body: <p>Say I have a collection Pastries like this :</p>
  
  <pre><code>[
      { 
      name: "chocolate",
      theyLikeIt : [{value:"Paul"}, {value:"Oliver"}, {value:"John"}]
      },
      { 
      name: "banana",
      theyLikeIt : [{value:"Sarah"}, {value:"John"}]
      }
  ]
  </code></pre>
  
  <p>How could I retrieve all the pastries that John likes ? 
  In Mongo it would be something like : </p>
  
  <pre><code>find({ theyLikeIt: { $elemMatch: { $eq: JohnId } } })
  </code></pre>