Answer by Just code for How to get value from custom attribute in angular 5?

instead of getting the newsId you can just pass it as parameter on click

(click)="loadnewsdetail(news.NewsId)"

and get it like this.

 loadnewsdetail(newsId) {    alert(newsId);  }

or if you want to get the attribute you can pass an event to the function (actually not needed in your case). but, here is how you can do it.

(click)="loadnewsdetail($event)"

and get that value using

loadnewsdetail(newsId) {     alert(newsId.target.getAttribute("newsid"));}

demo