Error Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException [migrated]
- by user134212
I'm new here.
I'm learning how to program on java and I have a problem with my code.
I really have no clue why my code is not working.
I think my mistake may be here, but I'm not quite sure.
m3 = new Matriz(ren2,col2);
btSumar.addActionListener(new ActionListener()
{
Matriz m3;//(ren2,col2);
public void…