title: Javascript delete an object key array value
body: <p>I have this object:</p>
  
  <pre><code>object = {
     key:["1","2","3","4","5"],
     key2:["5","7","8","9"]
  }
  </code></pre>
  
  <p>How do I delete an object key and how to delete an object key value ?</p>