Loading the built-in jQuery in Joomla 4 if it does not exist

Question

Tell me please. How to load jQuery in Joomla 4 if it has not been loaded yet?

Answer 1

You should be able to load it like so:

Joomla\CMS\HTML\HTMLHelper::_('jquery.framework');

Else, if you're using Joomla's Web Asset Manager, then you can define it as a dependency in your JSON object:

{
  "name": "foobar",
  "type": "script",
  "uri": "com_mycomponent/script.min.js",
  "dependencies": [
    "jquery"
  ]
},

Answer 2

Lodder answer is certainly useful, but not what I wanted to see. The correct loading of the embedded jquery looks like this.

use Joomla\CMS\Factory;

$wa = Factory::getApplication()->getDocument()->getWebAssetManager();
$wa->useScript('jquery');

This will work if jquery has not been loaded before.