How to generate unique ID in linked list? - c++

Question

I am currently learning how to use linked list in class in my free time. Now I only know how to insert, display and delete. I can delete by using int age; but I think it would be better if I'm able to generate a unique ID that is easier for user to remember(user-friendly), for each data in the linked list so that I could delete by its ID.
I want to know if there is a possible way for me to generate a unique ID in the getInput(); function?
If yes, please give me a hint how to do it. Thanks!
struct list
{
list *head, *tail;
list *next;
}
class node
{
private:
std::string name; // Name
int age; // Age in integer
float height; // In meters
public:
node *next; // Pointer to next node
node *head, *tail;
node *start_ptr = NULL; // Start Pointer (root)
node *temp;
node *temp2;
node *pNextValue;
node* prev; // empty header
node* current;
void printList();
void delete_end_node();
void search();
void sort_age();
void deletebyAge();
node()
{
head = NULL;
tail = NULL;
}
void getInput()
{
temp = new node;
cout << "ID: ";
// This is where I want to generate unique ID
cout << "Name: ";
cin >> temp->name;
cout << "Age: ";
cin >> temp->age;
cout << "Height: ";
cin >> temp->height;
cout<<"\n";
temp->next = NULL; // Sets the node to be the last node
if (start_ptr == NULL)
start_ptr = temp;
else
{
temp2 = start_ptr; // We know temp2 is not NULL - list not empty!
while (temp2->next != NULL) // The loop will terminate when temp2
temp2 = temp2->next; // points to the last node in the list
// Move to next link in chain
temp2->next = temp; // Sets the pointer from that last node to point to the node that has just declared
}
} // End of getInput() function
}; //End of class

Answer 1

In C++ the identity of an object is its address. You can use node address as its id, e.g.:
class node
{
private:
std::string name; // Name
int age; // Age in integer
float height; // In meters
friend std::ostream& operator<<(std::ostream& s, node& n) {
return s << "id:" << &n
<< ' ' << "name:" << n.name
<< ' ' << "age:" << n.age
<< ' ' << "height:" << n.height
<< '\n';
}
// the rest of your code...
};
And then print it like:
node n;
std::cout << n;
Alternatively, use a serial counter:
class node
{
private:
std::string name; // Name
int age; // Age in integer
float height; // In meters
unsigned const id;
static unsigned object_counter;
public:
node()
: id(++object_counter)
{}
friend std::ostream& operator<<(std::ostream& s, node& n) {
return s << "id:" << n.id
<< ' ' << "name:" << n.name
<< ' ' << "age:" << n.age
<< ' ' << "height:" << n.height
<< '\n';
}
// the rest of your code...
};
unsigned node::object_counter = 0;