title: Property 'form' has no initializer and is not definitely assigned in the constructor
body: <p>Here is my component.ts:</p>
  <pre><code>import { Component, OnInit } from '@angular/core';
  import { Validators, FormControl, FormGroup, FormBuilder } from '@angular/forms';
  
  @Component({
    selector: 'app-microplate',
    templateUrl: './microplate.component.html',
    styleUrls: ['./microplate.component.css']
  })
  export class MicroplateComponent implements OnInit {
    form: FormGroup;
  
    ngOnInit(): void {
      this.form = new FormGroup({
        columns: new FormControl('some value', [
          Validators.required
        ])
      });
    }
  
    get columns() { return this.form.get('columns'); }
  }
  </code></pre>
  <p>Here is my component.html:</p>
  <pre><code>&lt;form [formGroup]=&quot;form&quot;&gt;
      &lt;label for=&quot;columns&quot;&gt;&lt;b&gt;Columns: &lt;/b&gt;&lt;/label&gt;
      &lt;input id=&quot;columns&quot; type=&quot;text&quot; [formControlName]=&quot;columns&quot;&gt;
  &lt;/form&gt;
  </code></pre>
  <p>I get the following error message at <code>form: FormGroup;</code>:</p>
  <p><code>Property 'form' has no initializer and is not definitely assigned in the constructor.</code></p>
  <p>I have used the information from Angular website, but I cannot solve the issue. Any help would be appreciated.</p>