nested formarray in angular 8

 
import { Component } from '@angular/core';
  import { FormGroup, FormArray, FormBuilder } from '@angular/forms'
 
 
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent  {
  
  title = 'Nested FormArray Example Add Form Fields Dynamically';
 
  empForm:FormGroup;
 
 
  constructor(private fb:FormBuilder) {
 
    this.empForm=this.fb.group({
      employees: this.fb.array([]) ,
    })
  }
 
 
  employees(): FormArray {
    return this.empForm.get("employees") as FormArray
  }
 
 
  newEmployee(): FormGroup {
    return this.fb.group({
      firstName: '',
      lastName: '',
      skills:this.fb.array([])
    })
  }
 
 
  addEmployee() {
    console.log("Adding a employee");
    this.employees().push(this.newEmployee());
  }
 
 
  removeEmployee(empIndex:number) {
    this.employees().removeAt(empIndex);
  }
 
 
  employeeSkills(empIndex:number) : FormArray {
    return this.employees().at(empIndex).get("skills") as FormArray
  }
 
  newSkill(): FormGroup {
    return this.fb.group({
      skill: '',
      exp: '',
    })
  }
 
  addEmployeeSkill(empIndex:number) {
    this.employeeSkills(empIndex).push(this.newSkill());
  }
 
  removeEmployeeSkill(empIndex:number,skillIndex:number) {
    this.employeeSkills(empIndex).removeAt(skillIndex);
  }
 
  onSubmit() {
    console.log(this.empForm.value);
  }
 
 
}
 
 
export class country {
  id: string;
  name: string;
 
  constructor(id: string, name: string) {
    this.id = id;
    this.name = name;
  }
}
 
 
 
 
<h1>{{title}}</h1>
 
<form [formGroup]="empForm" (ngSubmit)="onSubmit()">
 
  <div formArrayName="employees">
 
    <div *ngFor="let employee of employees().controls; let empIndex=index">
 
      <div [formGroupName]="empIndex" style="border: 1px solid blue; padding: 10px; width: 600px; margin: 5px;">
        {{empIndex}}
        First Name :
        <input type="text" formControlName="firstName">
        Last Name:
        <input type="text" formControlName="lastName">
 
        <button (click)="removeEmployee(empIndex)">Remove</button>
 
 
        <div formArrayName="skills">
 
          <div *ngFor="let skill of employeeSkills(empIndex).controls; let skillIndex=index">
 
 
 
            <div [formGroupName]="skillIndex">
              {{skillIndex}}
              Skill :
              <input type="text" formControlName="skill">
              Exp:
              <input type="text" formControlName="exp">
 
              <button (click)="removeEmployeeSkill(empIndex,skillIndex)">Remove</button>
 
            </div>
 
          </div>
          <button type="button" (click)="addEmployeeSkill(empIndex)">Add Skill</button>
        </div>
 
 
      </div>
 
    </div>
  </div>
 
  <p>
    <button type="submit">Submit</button>
  </p>
 
</form>
 
 
<p>
  <button type="button" (click)="addEmployee()">Add Employee</button>
</p>
 
{{this.empForm.value | json}}