Mobile Websites » Frage 15

17. November 2019 Kategorie(n): Google Schlagwörter: Alte Google Fragen

Google Prüfung

Google Mobile Websites » Frage 15

Wenn Sie eine Animation wie Scrolling verwenden, sollte Ihr JavaScript ungefähr folgende Ladezeit aufweisen:

5-6 ms
9-10 ms
7-8 ms
3-4 ms

Begründung:

60fps and Device Refresh Rates

Most devices today refresh their screens 60 times a second. If there’s an animation or transition running, or the user is scrolling the pages, the browser needs to match the device’s refresh rate and put up 1 new picture, or frame, for each of those screen refreshes.

Each of those frames has a budget of just over 16ms (1 second / 60 = 16.66ms). In reality, however, the browser has housekeeping work to do, so all of your work needs to be completed inside 10ms. When you fail to meet this budget the frame rate drops, and the content judders on screen. This is often referred to as jank, and it negatively impacts the user’s experience.

Alter Link zur Lösung von Google: https://developers.google.com/web/fundamentals/performance/rendering/