MEAN Angular Routing and Forms 2

Question 1

In Angular template-driven forms, which directive does Angular automatically apply to all <form> elements?

Accepted Answer

ngForm

Answer

Angular automatically applies the ngForm directive to all <form> elements, creating an NgForm instance that tracks the form's validity, value, and submission state.

Question 2

Which directive creates two-way data binding between a form input and a component property in template-driven forms?

Accepted Answer

[(ngModel)]

Answer

[(ngModel)] uses the banana-in-a-box syntax to create two-way data binding, synchronizing the input element value with the component property in both directions.

Question 3

What CSS class does Angular add to a form control that fails validation?

Accepted Answer

ng-invalid

Answer

Angular adds the ng-invalid class to any form control that fails validation, regardless of whether the user has interacted with it.

Question 4

How do you enable the built-in 'required' validator on an input field in a template-driven Angular form?

Accepted Answer

required

Answer

Adding the standard HTML5 'required' attribute to an input that also has ngModel activates Angular's built-in required validator.

Question 5

How do you create a template reference variable that holds the NgForm directive instance for validity checks?

Accepted Answer

#myForm="ngForm"

Answer

Using #myForm="ngForm" exports the NgForm directive instance into the template variable, enabling expressions like myForm.valid or myForm.submitted.

MEAN - Stack Development Practice Test

MEAN - Stack Development Practice Test

MEAN Angular Routing and Forms 2