Hi, I'm having a strange problem with my linked list program.
This is slightly embarrassing because I'm getting back to coding in C++ after 4 years and don't remember much.

This is the code


void printList(struct node *&);

struct node
node* next;
int data;

int main()

node *node1, *node2, *node3, *node4;
node1->data = 1;
node2->data = 2;
node3->data = 3;
node4->data = 4;

node1->next = node2;
node2->next = node3;
node3->next = node4;
node4->next = node1;


return 0;

void printList(node*& head)
node* current = head;
int counter = 0;
while(current != NULL && counter < 10)
cout<<"\n "<<current->data;
current = current->next;

It doesn't seem to be accessing node4, could someone point me towards what's wrong? Thanks.


okay, changed the code to

node *node1 = new node;

Thanks! Why did it print the first three nodes though? How did it allocate memory if I didn't allocate memory initially?

Since your pointers are located on the stack they got the values that happen to be there, which might be a valid memory address, or not. A function's stack frame, which is the memory that the compiler allocates for your local variables, is not cleared (set to 0) when a function returns or when a new stack frame is allocated (normally). This means that the stack may contain more than just random data since parts of previous stack frames might be reused.

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