function claass() {
echo '';
}
add_action('wp_head', 'claass')
Warning: require(C:\wwwroot\wxdcjs.net/wp-includes/default-constants.php): failed to open stream: No such file or directory in C:\wwwroot\wxdcjs.net\wp-settings.php on line 21
Fatal error: require(): Failed opening required 'C:\wwwroot\wxdcjs.net/wp-includes/default-constants.php' (include_path='.;C:\php\pear') in C:\wwwroot\wxdcjs.net\wp-settings.php on line 21