ganqqwerty · June 18, 2019 18:14
diff --git a/app.component.ts b/app.component.ts
 this.myForm.get('myCheckbox').valueChanges
    .subscribe(value => {
        this.myForm.get('myEmailField').updateValueAndValidity();
    });
	this.myForm.get('myCheckbox').valueChanges
	.subscribe(value => {
	this.myForm.get('myEmailField').updateValueAndValidity();
	});