set default boolean false in formcontrol (primary field) ko
this.contactForm = new FormGroup({
name: new FormControl('', [ Validators.required]),
contact: new FormControl('', [ Validators.required,Validators.minLength(10)]),
email: new FormControl('', [ Validators.required,Validators.email]),
primary: new FormControl('',[])
});
HTML File :- please see html file
<form [formGroup]="contactForm">
<mat-checkbox class="example-margin" formControlName="primary" [value]="primary" [(ngModel)]="primary"> Make this primary </mat-checkbox>
</form>
First argument of FormControl gets initial value, so you can easily write:
new FormControl(false, [...]);
Or it could be more complex if you need:
new FormControl({ value: false, disabled: true }, [...]);