What Does `return false` Do in a Link's `onclick` Event Handler?

Understanding the Role of 'return false' in Click Event Listeners

In HTML documents, it is common to encounter links such as the following:

<a href='#' onclick='someFunc(3.1415926); return false;'>Click here !</a>

The presence of the return false statement at the end of the onclick event handler prompts the question: what does it actually do?

Effect of 'return false'

The return value of an event handler dictates whether the default browser behavior for that event should occur. In the case of a click event on a link, the default behavior is to navigate to the specified URL. However, with return false, this default action is prevented.

Alternative in Buttons

Unlike links, buttons do not typically have return false in their click event handlers. Buttons have their own behavior, such as submitting a form or triggering an action. Interrupting this default behavior requires the use of other techniques, such as e.preventDefault() or manipulating the button.type property.

Specification

It's important to note that the behavior of return false in click event handlers is not defined by any W3C specification. It originates from the Netscape 2 era, often referred to as "DOM 0".

Modern Alternative

For modern web development practices, it is recommended to use event.preventDefault() instead of return false. preventDefault() is explicitly defined in the DOM 2 Events specification and provides a more standardized approach to controlling default event behavior.

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