how to access model or view variable in angular 4 for two way data binding

Question

there is no scope variable in Angular 2+.

In Angular 2+ there is NgModel which helps you with two way binding.

https://angular.io/api/forms/NgModel

To access value of text area in your component.

In html

<textarea class="form-control" [(NgModel)]=comment placeholder="Add Comment">
<input type="button" value="Add" (click)="AddComment()" />

In component:

comment:any="";

AddComment(){

console.log(this.comment);
}

Here comment var will always be mapped to inputs in textarea.