angular formarray valuechanges code example

Example 1: patch value in form array

this.items.at(index).patchValue(...);

for patching value in a formArray

Example 2: angular 9 form value changes

this.reactiveForm.get("firstname").valueChanges.subscribe(selectedValue => {
  console.log('firstname value changed')
  console.log(selectedValue)                              //latest value of firstname
  console.log(this.reactiveForm.get("firstname").value)   //latest value of firstname
})