Example of how to implement a templated linked list in C++

// Example of how to implement a templated linked list
#include <iostream>
#include <string>
using namespace std;

class Cat {
public:
Cat(string name = "unnamed", int age = 0): name(name), age(age) { }
const string name;
int age;
friend ostream& operator<<(ostream& os, Cat* cat) {
os << "Cat: { name: "<< cat->name << ", age: " << cat->age << " }";
return os;
}
};

template<class T>
class LinkedList {
private:
class Node {
friend class LinkedList;
T data;
Node* next;
Node(T data, Node* next = NULL): data(data), next(next) { }
};
Node* head;
public:
LinkedList(): head(NULL) { }
~LinkedList() {
Node* currentNode = head;
Node* nextNode = NULL;

while (currentNode != NULL) {
nextNode = currentNode->next;
delete currentNode;
currentNode = nextNode;
}
}
void append(T data) {
Node* newNode = new Node(data);
if (head == NULL) {
head = newNode;
} else {
Node* currentNode = head;
while (currentNode->next != NULL) {
currentNode = currentNode->next;
}
currentNode->next = newNode;
}
}
void prepend(T data) {
Node* newNode = new Node(data, head);
head = newNode;
}
T getAtIndex(int index) const {
Node* currentNode = head;
while (currentNode != NULL) {
if (index == 0) {
return currentNode->data;
}
currentNode = currentNode->next;
index--;
}
return NULL;
}
void removeAtIndex(int index) {
if (index == 0) {
Node* newHead = head->next;
delete head;
head = newHead;
} else {
Node* prevNode = NULL;
Node* currentNode = head;
while (currentNode != NULL) {
if (index == 0) {
prevNode->next = currentNode->next;
delete currentNode;

}
prevNode = currentNode;
currentNode = currentNode->next;
index--;
}
}
}
friend ostream& operator<<(ostream& os, const LinkedList& linkedList) {
os << "[";
Node* currentNode = linkedList.head;
while (currentNode != NULL) {
os << currentNode->data << ((currentNode->next == NULL) ? "" : ", ");
currentNode = currentNode->next;
}
os << "]";
return os;
}
};


int main(int argc, const char * argv[]) {
LinkedList<int> intList = LinkedList<int>();
intList.append(3);
intList.append(4);
intList.append(5);
intList.append(6);
intList.append(100);

intList.prepend(1);
intList.removeAtIndex(5);
intList.removeAtIndex(0);
intList.removeAtIndex(2);
cout << intList << endl; // [3, 4, 6]
cout << "Number at index 1: " << intList.getAtIndex(1) << endl; // Number at index 1: 4

LinkedList<Cat*> catList = LinkedList<Cat*>();
catList.append(new Cat("Estabon", 2));
catList.append(new Cat("Cat-Man", 8));
cout << catList << endl; // [Cat: { name: Estabon, age: 2 }, Cat: { name: Cat-Man, age: 8 }]

return 0;
}

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