Q
What is event delegation in JavaScript/jQuery?

Answer & Solution

Answer: Option C
Solution:
Event delegation is a technique where you attach a single event handler to a parent element that will fire for all descendants matching a specified selector, even those added dynamically after the handler has been attached.
Related Questions on Average

How does event delegation help in handling dynamically added DOM elements?

A). By attaching event handlers to parent elements, ensuring consistent handling.

B). By removing event handlers from the DOM altogether.

C). By binding event handlers directly to dynamically added elements.

D). By refreshing the page whenever new elements are added.

What is the primary advantage of using event delegation in web development?

A). Simplifies event handling by attaching handlers directly to individual elements.

B). Ensures events are captured on dynamically added elements.

C). Increases the complexity of event handling logic.

D). Requires manual refreshing of the page whenever new elements are added.

How does event delegation contribute to better performance in web applications?

A). By reducing the number of event handlers attached to individual elements.

B). By increasing the number of event handlers attached to individual elements.

C). By requiring manual refreshing of the page whenever new elements are added.

D). By preventing events from bubbling up the DOM tree.

How does event delegation simplify event handling in web development?

A). By attaching event handlers to parent elements instead of individual elements.

B). By requiring manual refreshing of the page whenever new elements are added.

C). By removing events from the DOM altogether.

D). By triggering events programmatically.

What is the syntax for using event delegation with jQuery's .on() method?

A). $(parentElement).on(eventType, childSelector, eventHandler);

B). $(childElement).on(eventType, parentSelector, eventHandler);

C). $(parentElement).delegate(eventType, childSelector, eventHandler);

D). $(childElement).delegate(eventType, parentSelector, eventHandler);

When is event delegation particularly useful in web development?

A). When events need to be triggered programmatically.

B). When dealing with a static DOM structure.

C). When handling events on elements that are dynamically added or removed.

D). When preventing events from bubbling up the DOM tree.

What happens if the parent element specified for event delegation is removed from the DOM?

A). The event delegation mechanism will no longer work for child elements.

B). The child elements will inherit the event handlers of the parent element.

C). The child elements will trigger the event handlers directly.

D). The event will be captured by the browser's default event handler.

How does event delegation help in handling events on dynamically added table rows?

A). By attaching event handlers to the parent table element.

B). By attaching event handlers directly to the dynamically added table rows.

C). By manually refreshing the page whenever new rows are added.

D). By using regular expressions to match table rows.

Which jQuery method provides better performance for event delegation: .on() or .click()?

A). .on()

B). .click()

C). Both methods provide similar performance.

D). It depends on the browser being used.

What is the advantage of using event delegation in single-page applications (SPAs)?

A). It ensures that events are captured on dynamically generated content.

B). It allows events to be triggered programmatically.

C). It prevents events from bubbling up the DOM tree.

D). It requires fewer resources compared to traditional web applications.