Generate a class attribute from an array of classes and sanitises the classes

class-att-example.php

<?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>

class-attr.php

<?php

/**
 * Generates a class attribute for a HTML element and sanitises the classes
 * We can't just run `sanitize_html_class` on imploded classes as the spaces will be stripped out
 * So we have to loop through each class and sanitise each class individually
 *
 * @param array $classes The classes to add to the element.
 * return string The generated class attribute, or an empty string if the array is empty
 */
function cameronjonesweb_generate_class_attribute( $classes ) {
	$class_attr = ! empty( $classes ) && is_array( $classes ) ? 'class="' . implode( ' ', array_map( function( $class ) {
		return sanitize_html_class( $class );
	}, $classes ) ) . '"' : '';
	return $class_attr;
}