How to run a javascript function in HTML page only when a dropdown menu is selected, before any option is selected in it. I run Query when dropdown menu is clicked on, with the following:

$("#_id").click(function () {

Then when I select something in the same dropdown menu, script runs again. When it's clicked on dropdown menu and when an option is selected. How to prevent from running again when I select something?

CodePudding user response：

What is the usecase? We prefer dropdowns to only do stuff when we change them

To answer:

Mousedown triggers before click

Click and hold the mouse to see the mousedown, release to see the click

$("#_id").on("click",function() { console.log("clicked")});
$("#_id").on("mousedown",function() { console.log("mousedown")});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<select id="_id">
<option value="">Please select</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>