> For the complete documentation index, see [llms.txt](https://mobius-studios.gitbook.io/selectable/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mobius-studios.gitbook.io/selectable/api/methods/once.md).

# once()

<pre class="language-javascript"><code class="lang-javascript">/**
<strong> * @param  {String} event name
</strong> * @param  {Function} callback
 * @return {Void}
 */
once(eventName, callback)
</code></pre>

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Adds a custom event listener to an instance that will be removed after being fired.

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### Example