Difference between ArrayList, LinkedList and Vector

ArrayList:

Array List is an implemented class of List interface which is present in package java.util. Array List is created on the basis of the growable or resizable array. And Array List is an index-based data structure. In ArrayList, the element is stored in a contiguous location.  It can store different data types. And random access is allowed. We can also store the duplicate element in Array List. It can store any number of null values.

 Below is the implementation of ArrayList:

Java

// Java program to Illustrate working of an ArrayList

// Importing required classes
import java.io.*;
import java.util.*;

// Main class
class GFG {

    // Main driver method
    public static void main(String[] args)
    {
        // Creating an ArrayList of Integer type
        ArrayList<Integer> arrli = new ArrayList<Integer>();

        // Appending the new elements
        // at the end of the list
        // using add () method via for loops
        for (int i = 1; i <= 5; i++)
            arrli.add(i);

        // Printing the ArrayList
        System.out.println(arrli);

        // Removing an element at index 3
        // from the ArrayList
        // using remove() method
        arrli.remove(3);

        // Printing the ArrayList after
        // removing the element
        System.out.println(arrli);
    }
}

Output

[1, 2, 3, 4, 5]
[1, 2, 3, 5]

Linked List:

Linked list is a linear data structure where data are not stored sequentially inside the computer memory but they are link with each other by the address. The best choice of linked list is deletion and insertion and worst choice is retrieval . In Linked list random access is not allowed . It traverse through iterator. 

 Below is the implementation of the LinkedList:

C++

#include <iostream>

// LinkedList class definition
class LinkedList {
 public:
  // Node structure definition within LinkedList class
  struct Node {
    int data;
    Node *next;
    // Node constructor
    Node(int d) : data(d), next(nullptr) {}
  };

  // Pointer to head node
  Node *head;

  // Constructor
  LinkedList() : head(nullptr) {}

  // Function to print the linked list
  void printList() {
    // Pointer to traverse the linked list
    Node *n = head;
    while (n != nullptr) {
      // Print the data of the node
      std::cout << n->data << " ";
      // Move to the next node
      n = n->next;
    }
  }
};

// Main function
int main() {
  // Create an instance of the LinkedList class
  LinkedList llist;

  // Create three nodes with data 1, 2 and 3
  llist.head = new LinkedList::Node(1);
  LinkedList::Node *second = new LinkedList::Node(2);
  LinkedList::Node *third = new LinkedList::Node(3);

  // Connect the first node with the second node
  llist.head->next = second;
  // Connect the second node with the third node
  second->next = third;

  // Call the printList function to print the linked list
  llist.printList();

  return 0;

}

Java

import java.util.*;

// LinkedList class definition
class LinkedList {

  // Node class definition within LinkedList class
  static class Node {
    int data;
    Node next;
    // Node constructor
    Node(int d) {
      this.data = d;
      next = null;
    }
  }

  // Pointer to head node
  Node head;

  // Constructor
  LinkedList() {
    head = null;
  }

  // Function to print the linked list
  void printList() {
    // Pointer to traverse the linked list
    Node n = head;
    while (n != null) {
      // Print the data of the node
      System.out.print(n.data + " ");
      // Move to the next node
      n = n.next;
    }
  }
}

// Main class
public class Main {
  public static void main(String[] args) {
    // Create an instance of the LinkedList class
    LinkedList llist = new LinkedList();

    // Create three nodes with data 1, 2 and 3
    llist.head = new LinkedList.Node(1);
    LinkedList.Node second = new LinkedList.Node(2);
    LinkedList.Node third = new LinkedList.Node(3);

    // Connect the first node with the second node
    llist.head.next = second;
    // Connect the second node with the third node
    second.next = third;

    // Call the printList function to print the linked list
    llist.printList();
    //This code is Contributed by Abhijit Ghosh
  }
}

C#

// C# program to define a LinkedList class

using System;

// LinkedList class definition
class LinkedList {
    // Node structure definition within LinkedList class
    public class Node {
      public int data;
      public Node next;
      // Node constructor
      public Node(int d) {
        data = d;
        next = null;
        }
    }
    // Pointer to head node
    public Node head;

    // Constructor
    public LinkedList() {
        head = null;
    }

    // Function to print the linked list
    public void PrintList() {
        // Pointer to traverse the linked list
        Node n = head;
        while (n != null) {
            // Print the data of the node
            Console.Write(n.data + " ");
            // Move to the next node
            n = n.next;
        }
    }
}

// Main function
class GFG {
static void Main() {
    // Create an instance of the LinkedList class
    LinkedList llist = new LinkedList();
        // Create three nodes with data 1, 2 and 3
        llist.head = new LinkedList.Node(1);
        LinkedList.Node second = new LinkedList.Node(2);
        LinkedList.Node third = new LinkedList.Node(3);

        // Connect the first node with the second node
        llist.head.next = second;
        // Connect the second node with the third node
        second.next = third;

        // Call the PrintList function to print the linked list
        llist.PrintList();
    }
}

Output

1 2 3 

Vector:

The Vector class implements a growable array of objects. Vectors fall in legacy classes, but now it is fully compatible with collections. It is found in java.util package and implement the List interface

 Below is the implementation of the Vector:

C++

#include <iostream>
#include<vector>
using namespace std;

int main()
{
   // Size of the Vector
int n = 5;
// Declaring the Vector with
// initial size n
vector<int> v;

// Appending new elements at
// the end of the vector
for (int i = 1; i <= n; i++)
    v.push_back(i);

// Printing elements
for(auto i : v)
    cout<<i<<" ";
cout<<endl;

// Remove element at index 3
v.erase(v.begin()+3);

// Displaying the vector
// after deletion
for(auto i : v)
    cout<<i<<" ";
cout<<endl;

return 0;
}

Java

// Java Program to Demonstrate Working
// of Vector Via Creating and using it

// Importing required classes
import java.io.*;
import java.util.*;

// Main class
class GFG {

    // Main driver method
    public static void main(String[] args)
    {
        // Size of the Vector
        int n = 5;

        // Declaring the Vector with
        // initial size n
        Vector<Integer> v = new Vector<Integer>(n);

        // Appending new elements at
        // the end of the vector
        for (int i = 1; i <= n; i++)
            v.add(i);

        // Printing elements
        System.out.println(v);

        // Remove element at index 3
        v.remove(3);

        // Displaying the vector
        // after deletion
        System.out.println(v);

        // iterating over vector elements
        // using for loop
        for (int i = 0; i < v.size(); i++)

            // Printing elements one by one
            System.out.print(v.get(i) + " ");
    }
}

Output

[1, 2, 3, 4, 5]
[1, 2, 3, 5]
1 2 3 5 

Difference between Array List, Linked List, and Vector:

Subject	Array List	Linked List	Vector
synchronized	Not present	Not present	present
Random access	Allowed	Not Allowed	Allowed
Memory Location	contiguous	Not contiguous	contiguous
Null values	supports	supports	supports
Data structure	Dynamic Array	Doubly Linked List	Dynamic Array
Duplicate allowed	Yes	Yes	Yes
Operation	Insertion and deletion are slow	Insertion and deletion are fast	Insertion and deletion are slow

Which one is better among Linked list, Array list, or Vector?

It depends on the specific use case, each of these data structures has its own advantages and trade-offs. If you mostly need to insert and delete elements at the start or middle of the container, then a linked list might be a better option. If you need fast random access and are willing to accept slower insertion and deletion at end positions, an Array List or Vector is a better option.