title: ERROR Error: this.validator is not a function
body: <p>I get this error after creating FormGroup.</p>
  <p><a href="https://i.stack.imgur.com/1WkBv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1WkBv.png" alt="image of the error" /></a></p>
  <p>I created a simple error template on <a href="https://stackblitz.com/edit/angular-example-this-validator-is-not-a-function?file=src/app/app.component.ts" rel="nofollow noreferrer">Stackblitz</a>.</p>
  <p>My sample data is as follows:</p>
  <p><a href="https://i.stack.imgur.com/jLV6L.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jLV6L.png" alt="enter image description here" /></a></p>
  <p>Create a FormGroup as shown below:</p>
  <p><a href="https://i.stack.imgur.com/xuiZU.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xuiZU.png" alt="enter image description here" /></a></p>
  <p>I understand that it is not possible to create FormGroup of a string array. Because the data does not have a key value to create a name for the form group.</p>
  <p>Is there a way to deal with this?</p>