title: How does *ngFor work in Angular when data is appended to existing array?
body: <p>I have an array say, <code>dataArray</code>, which has 100 items. I am using ngFor to show 100 checkboxes initially. There is a button to load next 100 items. On click of this button, I would append 100 more items to <code>dataArray</code>, with this <code>dataArray</code> shall have 200 items. My question is, does Angular run the ngFor loop again to build 2nd set of items (including 1st 100 items too) or is it smart enough to loop only the 2nd set of items (only 100) and append them to the existing DOM?</p>