title: How to patch values in formGroup with formArray in Angular?
body: <p>Once the user will click on the edit button, I want to patch data in the reactive form. Currently, I am able to patch value with normal fields. But unable patch values in Dynamic fields and Arrays.</p>
  
  <pre><code>ngOnInit() {
      this.registrationForm = this.fb.group({
        personal_details : this.fb.group({
          name: this.fb.group({
            first_name: [''],
            last_name: ['']
          }),
          about_yourself: [''],
          dob: [''],
          // lang: [''],
          languages_known: this.fb.array([]),
          willingly_to_travel: ['']
        }),
        technologies: this.fb.array([
          this.addTech()
        ]),
  
        certifications : this.fb.array([
          this.addCertificate()
        ]),
      });
      this.getAllTrainners();
    }
  </code></pre>
  
  <p><strong>When the user clicks on edit button following function will run :</strong> </p>
  
  <pre><code>editTrainner(trainner: Trainner) {
  this._trainnerservice.currentTrainner = Object.assign({}, trainner);
  this.registrationForm.patchValue({
        personal_details: { type: Object,
          name: { type: Object,
              first_name: this._trainnerservice.currentTrainner.personal_details.name.first_name,
              last_name: this._trainnerservice.currentTrainner.personal_details.name.last_name
          },
          dob: this._trainnerservice.currentTrainner.personal_details.dob,
          about_yourself: this._trainnerservice.currentTrainner.personal_details.about_yourself,
          languages_known: this.fb.array([this.addlanguages_known()]),
          willingly_to_travel: this._trainnerservice.currentTrainner.personal_details.willingly_to_travel
      }
  });
    }
    addlanguages_known(): any {
      const control = this.registrationForm.get('languages_known') as FormArray;
      this._trainnerservice.currentTrainner.personal_details.languages_known.forEach(x =&gt; {
          control.push(this.fb.control(''));
        });
    }
  </code></pre>