Event.preventdefault() vs. return false

javascript

event-handling

javascript-standards

vanilla-javascript

byAnton Shumikhin·Sep 17, 2024

To halt default browser action, use event.preventDefault(), while in a jQuery event, return false puts a stop to both the default action and event bubbling.

Example:

document.querySelector('a').addEventListener('click', (e) => e.preventDefault()); // I said, no link navigation buddy!

$('a').click(() => false); // Hold up! No navigation and bubbles burst.

Getting the hang of when to use event.preventDefault() and when to go for return false is key for sculpting a sturdy and predictable event handling landscape.

Behavior in Vanilla JavaScript

In pure JavaScript, specifically when using addEventListener, be aware that returning false does not halt event propagation. This sets apart jQuery's unique approach from the native DOM event system.

Controlling events with precision

For situations where you need to prevent just the default action while letting the event continue its journey up the DOM tree, opt for event.preventDefault(). It's a literal life-saver when other elements further up might be eavesdropping for the same event.

Err... Handling errors

One downside of return false is that if an error pops up upstream, this line might get skipped. On the other hand, with e.preventDefault(), the default actions are suppressed consistently, regardless of errors lurking around in other event handlers.

Deep diving with John Resig

John Resig's writings offer a profound understanding of jQuery's event management. Exploring his insights will equip you to effectively handle tangled event-related scenarios.

Strategy: Choose your weapon

In the battleground of advanced use cases, gleaning wisdom from expert discussions can help you formulate tailored event handling strategies suiting your unique needs.

Beyond jQuery

Going beyond jQuery's realm, delve into vanilla JavaScript landscapes. Resources like "You Don't Need jQuery!" shed light on contemporary library-independent event handling techniques.

Aligning with ECMAScript Standards and W3C Recommendations

Being fluent in the ECMAScript standards and W3C recommendations ensures your event prevention techniques are aligning with the broader language specifications.

Navigating event models

Remember, there is a gulf between handling events in the standard addEventListener and legacy IE models. Grasping these differences is your ticket to seamless cross-browser compatibility.

Click! Not so fast...

When you aim to prevent navigation on anchor clicks, you typically need to enlist event.preventDefault(). This ensures the browser won't sneak off following the href attribute's URL.