<?php
// Example.
$myclasses = [ 'my-class', 'some-other-class', '<script>console.log(hi);</script>' ];

printf(
	'<div %1$s>%2$s</div>',
	cameronjonesweb_generate_class_attribute( $myclasses ),
	'My content'
);

// Displays: ?>
<div class="my-class some-other-class scriptconsoleloghiscript">My content</div>