title: Getting "Property 'items' does not exist on type" Error but its defined in interface
body: <p>My VS Code keeps giving me the error that <code>Property 'items' does not exist on type 'K2ItemList[]'.</code> But I have already defined it in the interface file and I have also doubled checked it and I dont see why am I getting this error.</p>
  <p>What am I doing wrong here?</p>
  <p>My <code>k2-itemlist.ts</code> interface file has this:</p>
  <pre><code>export interface K2Itemlist {
      site: Site;
      items: Item[];
  }
  export interface Site {
      url: string;
      name: string;
  }
  export interface Item {
      id: string;
      title: string;
      alias: string;
      link: string;
    }
  </code></pre>
  <p>My component file has this:</p>
  <pre><code>loadData() {
      this.jsonService.getItemLists()
        .subscribe(
          (data: K2Itemlist[]) =&gt; {
            if (data.items.length) { //  &lt;== THIS IS WHERE I AM GETTING THE ERROR MESSAGE
              this.itemlist = this.itemlist.concat(data);
            }
          },
          (error) =&gt; {
            this.errorMessage = error;
          }
        )
    }
  </code></pre>
  <p>Here is the <code>console.log(data);</code>:
  <a href="https://i.stack.imgur.com/Y9oxF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Y9oxF.png" alt="enter image description here" /></a></p>
  <p>Here is the Json Data:</p>
  <pre><code>{
    &quot;site&quot;: {
      &quot;url&quot;: &quot;https://example.com&quot;,
      &quot;name&quot;: &quot;Example&quot;
    },
    &quot;items&quot;: [
      {
        &quot;id&quot;: &quot;2493&quot;,
        &quot;title&quot;: &quot;Introducing STEM&quot;,
        &quot;alias&quot;: &quot;introducing-stem&quot;,
        &quot;link&quot;: &quot;/articles/introducing-stem&quot;,
        &quot;catid&quot;: &quot;5&quot;,
        &quot;introtext&quot;: &quot;STEM refers to an integrated learning approach that introduces Science, Technology, Engineering and Mathematics through play-based activities.&quot;,
        &quot;fulltext&quot;: &quot;\r\n&lt;p&gt;Since the first few years are when the brain is developing most rapidly, it makes sense to incorporate STEM concepts, skills and dispositions in early childhood education.&lt;/p&gt;&quot;,
      }
    ]
  }
  </code></pre>
  <p>This is my <code>getItemLists()</code> service:</p>
  <pre><code>getItemLists(): Observable&lt;K2Itemlist[]&gt; {
  
         let _url:string = this.homeApi;
  
         return this.http.get&lt;K2Itemlist[]&gt;(_url)
          .pipe(
            catchError(this.handleError)
          );
      }
  </code></pre>