Execute an articulation at each keystroke:
Definition and Usage
ng-keydown mandate instructs AngularJS when the
console is utilized on the particular HTML element.
ng-keydown mandate from AngularJS won't abrogate the component's unique onkeydown occasion, both will be executed.
The request of a key stroke is:
Supported by <input>, <select>, <textarea>, and other editable elements.
|expression||An articulation to execute when a key is pressed.|