Code is complete, I just need an explanation on how this code functions. #include using namespace std; class node { public: double data; node* next; }; node* head; void addData(double val) { node *n...

Code is complete, I just need an explanation on how this code functions.

#include
using namespace std;
class node
{
    public:
    double data;
    node* next;
};
node* head;
void addData(double val)
{
    node *n = new node;
    n->data=val;
    n->next=NULL;
    if(head==NULL)
    {
        head=n;
    }
    else
    {
        node *ptr=head;
        while(ptr->next!=NULL)
        {
            ptr=ptr->next;
        }
        ptr->next=n;
    }
}

void addBack(double x)


{


    node *n = new node;


    n->data=x;


    n->next=NULL;


    node *ptr=head;


    while(ptr->next!=NULL)


    {


        ptr=ptr->next;


    }


    ptr->next=n;


}

void display()
{
    node *ptr=head;
    while(ptr!=NULL)
    {
        coutdata<",>
        ptr=ptr->next;
    }
    cout<>
}

int main()
{
    head=NULL;
    addData(4.7);
    addData(12.8);
    addData(14.7);
    addData(16.2);
    cout<"linked><>
    display();
    addBack(56.9);
    cout<"after adding="" node="" with="" data="" 56.9="" to="" the="" back="" of="" linked="">
    display();
    addBack(11.9);
    cout<"after adding="" node="" with="" data="" 11.9="" to="" the="" back="" of="" linked="">
    display();
    addBack(34.9);
    cout<"after adding="" node="" with="" data="" 34.9="" to="" the="" back="" of="" linked="">
    display();
 return 0;
}