title: Get key values from a collection in Laravel
body: <p>I have this collection</p>
  <pre><code>1 =&gt; {#27
        +&quot;id&quot;: 1
        +&quot;name&quot;: &quot;Zel&quot;
        +&quot;age&quot;: &quot;43&quot;
      }
  2 =&gt; {#28
        +&quot;id&quot;: 2
        +&quot;name&quot;: &quot;Kol&quot;
        +&quot;age&quot;: &quot;56&quot;
      }
  3 =&gt; {#29
        +&quot;id&quot;: 3
        +&quot;name&quot;: &quot;Mil&quot;
        +&quot;age&quot;: &quot;32&quot;
      }
  </code></pre>
  <p>and I would like to return an array with the key values as a string like this:</p>
  <pre><code>[
  'id',
  'name',
  'age',
  ]
  </code></pre>
  <p>Can someone help me with that, please?</p>