请参阅Laravel eloquent whereHas方法中的外部变量

The following code gives the error Undefined variable searchParam. Need help.

if($searchParam!=null){
        $results=Image::whereHas('subjects',function($q){
            $q->where('subject','LIKE','%'.$searchParam.'%');
        });

Try with -

$results=Image::whereHas('subjects',function($q) use ($searchParam){
     $q->where('subject','LIKE','%'.$searchParam.'%');
});