formgroup angular

1To set all FormGroup values use, setValue:
2
3this.myFormGroup.setValue({
4  formControlName1: myValue1, 
5  formControlName2: myValue2
6});
7To set only some values, use patchValue:
8
9this.myFormGroup.patchValue({
10  formControlName1: myValue1, 
11  // formControlName2: myValue2 (can be omitted)
12});

1let form: FormGroup = new FormGroup({});
2form.addControl(field_name, new FormControl('', Validators.required));

1this.myForm = this.fb.group({
2  name: ['', [Validators.required]],
3  contacts: this.fb.group({
4    email: ['', [Validators.email]],
5  })
6});
7
8<form [formGroup]="myForm" (ngSubmit)="onSubmit()">
9<mat-grid-list cols="2" rowHeight="85px">
10<!-- name -->
11<mat-grid-tile>
12  <mat-form-field>
13    <input matInput type="text" formControlName="name">
14    <mat-error *ngIf="form.controls.name.hasError('required')">Name required</mat-error>
15  </mat-form-field>
16</mat-grid-tile>   
17<!-- contacts -->
18<div formGroupName="contacts">
19	<!-- email -->
20	<mat-grid-tile>
21  		<mat-form-field>
22    		<input matInput type="text" formControlName="email">
23	    	<mat-error *ngIf="form.get('contacts').get('email').hasError('required')">Email required</mat-error>
24		</mat-form-field>
25	</mat-grid-tile>
26</div>
27</form>
28</mat-grid-list>

1      
2        content_copy
3      
4      const form = new FormGroup({
5  first: new FormControl('Nancy', Validators.minLength(2)),
6  last: new FormControl('Drew'),
7});
8
9console.log(form.value);   // {first: 'Nancy', last; 'Drew'}
10console.log(form.status);  // 'VALID'
11