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:
#include <iostream> #include <vector> using namespace std;
int main()
{ // Creating a vector of int type
vector< int > vec;
// Appending new elements
// at the end of the vector
// using push_back() method via for loops
for ( int i = 1; i <= 5; i++)
vec.push_back(i);
// Printing the vector
for ( int i = 0; i < vec.size(); i++)
cout << vec[i] << " " ;
cout << endl;
// Removing an element at index 3
// from the vector
// using erase() method
vec.erase(vec.begin() + 3);
// Printing the vector after
// removing the element
for ( int i = 0; i < vec.size(); i++)
cout << vec[i] << " " ;
cout << endl;
return 0;
} // This code is contributed by Akash Jha |
// 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);
}
} |
# Creating a list of integers my_list = []
# Appending new elements to the list using for loop for i in range ( 1 , 6 ):
my_list.append(i)
# Printing the list print (my_list)
# Removing an element at index 3 from the list my_list.pop( 3 )
# Printing the list after removing the element print (my_list)
|
// C# program to Illustrate working of an ArrayList // Importing required namespaces using System;
using System.Collections;
// Main class class GFG {
// Main driver method
static void Main( string [] args)
{
// Creating an ArrayList of integer type
ArrayList arrli = new ArrayList();
// 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
foreach ( int i in arrli) Console.Write(i + " " );
Console.WriteLine();
// Removing an element at index 3
// from the ArrayList
// using RemoveAt() method
arrli.RemoveAt(3);
// Printing the ArrayList after
// removing the element
foreach ( int i in arrli) Console.Write(i + " " );
Console.WriteLine();
}
} // This code is contributed by Akash Jha |
let vec = []; // Appending new elements // at the end of the vector // using push() method via for loops for (let i = 1; i <= 5; i++) {
vec.push(i); } // Printing the vector for (let i = 0; i < vec.length; i++) {
console.log(vec[i] + " " );
} console.log( "\n" );
// Removing an element at index 3 // from the vector // using splice() method vec.splice(3, 1); // Printing the vector after // removing the element for (let i = 0; i < vec.length; i++) {
console.log(vec[i] + " " );
} console.log( "\n" );
//This code is contributed by Akash Jha |
[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:
#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;
} |
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
}
} |
class LinkedList:
# Node structure definition within LinkedList class
class Node:
def __init__( self , data):
self .data = data
self . next = None
def __init__( self ):
# Pointer to head node
self .head = None
def printList( self ):
# Pointer to traverse the linked list
n = self .head
while n is not None :
# Print the data of the node
print (n.data, end = ' ' )
# Move to the next node
n = n. next
if __name__ = = '__main__' :
# Create an instance of the LinkedList class
llist = LinkedList()
# Create three nodes with data 1, 2 and 3
llist.head = LinkedList.Node( 1 )
second = LinkedList.Node( 2 )
third = 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()
|
// 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();
}
} |
class Node { constructor(data) { this .data = data;
this .next = null ;
} } class LinkedList { constructor() { this .head = null ;
} printList() { let n = this .head;
while (n != null ) {
console.log(n.data + " " );
n = n.next; } } } let llist = new LinkedList();
llist.head = new Node(1);
let second = new Node(2);
let third = new Node(3);
llist.head.next = second; second.next = third; llist.printList(); //This code is contributed by Akash Jha |
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:
#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 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) + " " );
}
} |
# Size of the List n = 5
# Declaring the List with initial size n v = []
# Appending new elements at the end of the list for i in range ( 1 , n + 1 ):
v.append(i)
# Printing elements print (v)
# Remove element at index 3 v.pop( 3 )
# Displaying the list after deletion print (v)
# Iterating over list elements using a for loop for i in range ( len (v)):
# Printing elements one by one
print (v[i], end = " " )
|
using System;
using System.Collections.Generic;
namespace ConsoleApp {
class Program {
static void Main( string [] args)
{
// Size of the List
int n = 5;
// Declaring the List with
// initial size n
List< int > lst = new List< int >();
// Appending new elements at
// the end of the List
for ( int i = 1; i <= n; i++)
lst.Add(i);
// Printing elements
foreach ( var i in lst) Console.Write(i + " " );
Console.WriteLine();
// Remove element at index 3
lst.RemoveAt(3);
// Displaying the List
// after deletion
foreach ( var i in lst) Console.Write(i + " " );
Console.WriteLine();
Console.ReadKey();
}
} } //This code is contributed by Akash Jha |
// Size of the Array let n = 5; // Declaring the Array with initial size n let v = []; // Appending new elements at the end of the Array for (let i = 1; i <= n; i++)
v.push(i);
// Printing elements console.log(v.join( " " ));
// Remove element at index 3 v.splice(3, 1); // Displaying the Array after deletion console.log(v.join( " " ));
|
[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.