How to check whether a form or a control is invalid or not in Angular 10 ?

In this article, we are going to check whether a form is invalid or not in Angular 10. invalid property is used to report that the control or the form is invalid or not.

Syntax:

form.invalid 

Return Value:

• boolean: the boolean value to check whether a form is invalid or not.

NgModule: Module used by the invalid property is:

• FormsModule

Approach: 

• Create the Angular app to be used.
• In app.component.html make a form using ngForm directive.
• In app.component.ts get the information using the invalid property.
• Serve the angular app using ng serve to see the output.

Example 1:

Output:

Reference: https://v17.angular.io/api/forms/AbstractControlDirective#invalid