Warning: in_array() expects parameter 2 to be array

Question

求助：报错：Warning: in_array() expects parameter 2 to be array, string given in D:phpStudyWWWzhutiwp-contentthemesthemeprofunctions.php on line 98

出错位置：

if ( $depth == 0 && ($args->depth)>=0 && in_array( 'menu-item-has-children', $item->classes )){
$class_names[] = 'menu-item-has-children';        
$atts_class[] = 'dropdown-toggle';        
$atts['data-toggle'] = 'dropdown';        
$caret = ' <span class="caret"></span></a>';
}

请问怎么修改啊