All challenges
Multiple ChoiceIntermediate 30s

Passive Listeners

addEventListener('touchstart', fn, {passive:true}) tells the browser:
Options
  1. 1Silently invokes preventDefault on behalf of the handler
  2. 2Signals the handler will never invoke preventDefault itself
  3. 3The handler won't call preventDefault, enabling scroll optimizations
  4. 4Means the handler never calls preventDefault at all here

Think you can answer under pressure?

Get matched and answer live questions in 3-minute 1v1 battles. Elo ranking, badge tiers and bragging rights on the line.

Play this in a 3-minute battle