Q:

TypeError: Cannot read property 'value' of undefined in Angular 7

I am new to Angular 7 and I'm creating a simple CRUD application, using reactive forms, based on this tutorial which uses the MEAN stack.  I developed the form as the tutorial suggested, but I'm getting the following error: 

TypeError: cannot read value property.  

Click here to see my full error stack trace
Listed below is my code:
<div class="form-group">
          <button (click)="addBusiness(person_name.value, business_name.value, business_gst_number.value)"
              [disabled]="angForm.pristine || angForm.invalid" 
              type="submit"
              class="btn btn-primary">
              Add Business
           </button>

Any help would be greatly appreciated! 

A:

Following the example you said, you had to add that piece of code to the previous code.  Maybe that's what you are missing. 
Update: 
I added that code in stackblitz and its working:
https://stackblitz.com/edit/angular-stack-55598617?file=src/app/app.component.html
Can you use stackblitz to reproduce your error?