android - Cannot assign value to specific textView in RecyclerView.Adapter -

i'm new android dev , wanted make app fragments , use recyclerview inside it. i'm getting error saying i'm trying use settext on null object. code looks :

public static class contentadapter extends recyclerview.adapter<contentadapter.viewholder> {         private static string[] newstitle = new string[] {...};         private static string[] newsdescs = new string[] {...};          public contentadapter(viewgroup parent) {}          @override         public void onattachedtorecyclerview(recyclerview recyclerview) {             super.onattachedtorecyclerview(recyclerview);         }          public static class viewholder extends recyclerview.viewholder {             textview titles;             textview descs;             public viewholder(layoutinflater inflater, viewgroup parent) {                 super(inflater.inflate(r.layout.item_list, parent, false));                 titles = (textview) parent.findviewbyid(r.id.list_title);                 descs = (textview) parent.findviewbyid(r.id.list_desc);             }         }           @override         public viewholder oncreateviewholder(viewgroup parent, int viewtype) {              return new viewholder(layoutinflater.from(parent.getcontext()), parent);          }          @override         public void onbindviewholder(viewholder holder, int position) {             holder.titles.settext(newstitle[position]); //here error             holder.descs.settext(newsdescs[position]);          }          @override         public int getitemcount() { return newstitle.length; }     } 

here correct example if view holder

public static class headervh extends recyclerview.viewholder {      public textview textview;      public headervh(view view){         super(view);         textview = (textview)view;     }  } 

you need pass in view object of row viewholder, not parent view object. example of oncreateviewholder()

@override public recyclerview.viewholder oncreateviewholder(viewgroup parent, int viewtype) {         view v = layoutinflater.from(parent.getcontext()).inflate(r.layout.list_item_setting_header, parent, false);       recyclerview.viewholder  vh = new headervh(v); return vh; } 

https://developer.android.com/reference/android/support/v7/widget/recyclerview.viewholder.html

https://www.bignerdranch.com/blog/recyclerview-part-1-fundamentals-for-listview-experts/