7. Inserting a node into a singly-linked list

// Node.h
class Node {
    Node* pnext;
public:
    int data;

    // Insert new node in front:
    void insert( Node* newNode )
    {
        newNode->pnext = pnext;
        pnext = newNode;
    }
};

The following diagram shows how it works:

To insert a new node into the list, program must keep track of the previous node.

Inserting a node before an existing one cannot be done.

#include "Node.h"
int main ( )
{
    Node A;
    Node B;
    Node C;

    A.data = 12;
    B.data = 99;
    C.data = 37;

    A.insert( &C );
    A.insert( &B );

    return 0;
}