title: Mongoose schema how to add an array
body: <p>I was wondering how can we add an array of string in a moongoose schema.</p>
  
  <p>I have the following code but it is not working:</p>
  
  <pre><code>var message = new Schema({
      topic: String,
      content: String,
      restriction:String,
      sender:String,
      reciever:String,
      users:[String],
      read:{type: String, default: 'no'},
      like:{ type: Number, default: 0 },
      created_at: {type: Date, default: Date.now}
  });
  </code></pre>
  
  <p>I am talking about <code>users</code>. Can you help?</p>