How to Prevent Mysterious Onclick Execution Upon Page Load?

Javascript onclick function mysteriously triggering upon page load

The onclick event listener should only execute upon the click of the associated element. However, in certain scenarios, it can be observed that the function is being called immediately upon page load, rendering the click event ineffective.

This issue commonly arises when assigning the onclick attribute as setAttribute('onclick', secondFunction()) instead of setAttribute('onclick', secondFunction). The former directly executes the function, while the latter registers it as an event handler.

Correct Usage:

<code class="javascript">// Create a new element with an onclick event listener
var sentNode = document.createElement('a');
sentNode.setAttribute('href', "#");
sentNode.setAttribute('onclick', secondFunction);</code>

Incorrect Usage:

<code class="javascript">// Immediately executes the function upon loading the page
sentNode.setAttribute('onclick', secondFunction());</code>

The key distinction lies in the parentheses appended to secondFunction. By omitting them, the code defines the event handler as a reference to the function, allowing it to be executed when the element is clicked. Conversely, including the parentheses triggers the execution of the function right away.

By adhering to this correct usage, the onclick event will function as intended, awaiting the click of the associated element to be invoked.

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