Change the selected value of a select depending on an input in Angular

Question

I have this form. Which if the temperature of a person is greater than 38°C degrees the value of a select must change from healthy to sick if it's selected.

<form [formGroup]="form">
  <select formControlName="health" required>
  <option value="HEALTHY">Healthy</option>
  <option value="SICK">Sick</option>
  </select>
  <input (focusout)="changeValue($event)" type="number" 
   formControlName="temperature" required>
  </form>

When it is finished writing the function changeValue is called and this is how I am trying to change the value of the selected option.

ngOnInit() { 
  this.form = this.formBuilder.group({
    health: ["", Validators.required],
    temperature: ["", Validators.required],
})}
change(temperature){
  if(temperature > 38){
     this.form = this.formBuilder.group({
     temperature: ["SICK"],
})}
}

Answer 1

There are some bits you can do better when using reactive forms

Check the following

https://stackblitz.com/edit/angular-ivy-pytdtp

Answer 2

You need to reference the formControl you want to change directly and use it's.setValue() method.

so in the method you call on change, you can say this.form.get('temperature').setValue('SICK').