#include "Singlylinkednode.h" Singlylinkednode::Singlylinkednode() { this->setvalue(0); this->next=NULL; // can't set pointers equal to 0 you set them equal to$ } Singlylinkednode::Singlylinkednode(int value) { this->setvalue(value); // since this is a child class it can't directly$ this->next=NULL; }