wp-includes/formatting.php:2417Sanitizes an HTML classname to ensure it only contains valid characters.
$classnamestring$fallbackstringoptional''stringOne hook fires while sanitize_html_class() runs, in this order:
Filters a sanitized HTML class string.
function sanitize_html_class( $classname, $fallback = '' ) { // Strip out any percent-encoded characters. $sanitized = preg_replace( '|%[a-fA-F0-9][a-fA-F0-9]|', '', $classname ); // Limit to A-Z, a-z, 0-9, '_', '-'. $sanitized = preg_replace( '/[^A-Za-z0-9_-]/', '', $sanitized ); if ( '' === $sanitized && $fallback ) { return sanitize_html_class( $fallback ); } /** * Filters a sanitized HTML class string. * * @since 2.8.0 * * @param string $sanitized The sanitized HTML class. * @param string $classname HTML class before sanitization. * @param string $fallback The fallback string. */ return apply_filters( 'sanitize_html_class', $sanitized, $classname, $fallback );}Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/formatting.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.