title: Iterating an interface array with `forEach()`
body: <p>I'm new to Typescript and I'd like to save the response of an HTTP GET to an array of a type defined by an interface.</p>
  <pre class="lang-js prettyprint-override"><code>getErrors() {
    return this.http.get&lt;ErrorsInterface[]&gt;(environment.apiUrl+'errors').toPromise()
  }
  </code></pre>
  <p>Then I declare the array like this and call the function <code>getErrors()</code></p>
  <pre class="lang-js prettyprint-override"><code>errorsData: ErrorsInterface[]= []
  
  this.errorsData = await this.ErrorsService.getErrors()
  this.errorsData.forEach(res =&gt; {
   console.log(res.number)
  })
  </code></pre>
  <p>But I receive the following error:</p>
  <blockquote>
  <p>ERROR Error: Uncaught (in promise): TypeError: this.errorsData.forEach
  is not a function TypeError: this.errorsData.forEach is not a function</p>
  </blockquote>
  <p>I appreciate any help</p>