Create MCQA for the topic: Event Bubbling & Event Capturing

[kirandash]

Please create an MCQA to be added as question number 45.

The multiple choice question should be on the topic "Event Bubbling & Event Capturing". The difficulty level should be "Easy/Medium"

Tasks:

• [ ] add your code to 045 folder under code
• [ ] add your question to 45 in README.md file
• [ ] create a video explanation and upload on YouTube (optional)

Explanation:

• Target generates event. And event.target returns the reference of element which raised the event
• event propagates bottom to top like a bubble
• to stop default propagation, use: event.stopPropagation()
• To get the reverse behaviour i.e. event flow from top to bottom: we use Event Capturing
  • addEventListener(evt, fn, phase) phase: false by default - bubble phase, add it as true to make capture phase

Qns that are asked in interviews:

• Which is the default propagation path ?
  • ans: bottom to top
• How can you stop the event propagation ?
  • event.stopPropagation()
• How can you change the default propagation path ? (PROBABLY THE BEST QUESTION TO ASK)
  • addEventListener("click", btn, true)
• How can you get the reference of element on which event is fired ?
  • event.target