Java list | Arraylist in java | Java ArrayList-AapKiApniSchool

 In this blog we will learn Java List and ArrayList in Java. Different Different type of List and Commonly used methods.

Java list | Arraylist in java

List: List is an interface in java that's implementation is given by ArrayList,LinkedList,Stack and Vector. List extends Collection interface.

Synatx for instantiate the List interface.

List <data-type> list1= new ArrayList();
List <data-type> list2 = new LinkedList();
List <data-type> list3 = new Vector();
List <data-type> list4 = new Stack();

Collection Interface Main Methods:

public boolean add(E e)
public boolean addAll(Collection<? extends E> c)
public boolean remove(Object element)
public boolean removeAll(Collection<?> c)
default boolean removeIf(Predicate<? super E> filter)
public void clear()
public int size()
public Object[] toArray()
default Stream<E> stream()

ArrayList:

ArrayList implements List interface in java. It is a Array with dynamic size. It main inseration order and it is not thread safe. The elements stored in the ArrayList class can be randomly accessed. It can store duplicate data.

package com.mkyong;

import java.util.ArrayList;

import java.util.List;

public class ListDemo {

public static void main(String[] args) {

List<String> list= new ArrayList<>();

list.add("Sunil");

list.add("anil");

list.add("Narendra");

System.out.println("List "+list);

}

}

LinkedList: 

LinkedList implements List interface. It don't maintain insertion order. It can store duplicate data. We can't access random data from LinkedList.It is not thread safe. Adding new element in Linkedlist is fast as compare to ArrayList.It maintain the inseration order. Internally it use LinkedList for storing data.

package com.mkyong;

import java.util.LinkedList;

import java.util.List;

public class ListDemo {

public static void main(String[] args) {

List<String> list= new LinkedList<>();

list.add("Sunil");

list.add("anil");

list.add("Narendra");

list.add("Sunil");

System.out.println("List "+list);

}

}

Vector: 

Vector is similar to ArrayList but it is thread safe. Vector also internally use dynamic array.

package com.mkyong;

import java.util.List;

import java.util.Vector;

public class ListDemo {

public static void main(String[] args) {

List<String> list= new Vector<>();

list.add("Sunil1");

list.add("anil");

list.add("Narendra");

list.add("Sunil");

System.out.println("List "+list);

}

}

Stack:

Stack is a sub class of Vector. It contain all the methods of Vector and some additional methods like push,peek and pop. Push is used to insert data.Pop is used to remove data. Stack use First-In Last-Out DataStructure.

package com.mkyong;

import java.util.List;

import java.util.Stack;

public class ListDemo {

public static void main(String[] args) {

List<String> list= new Stack<>();

list.add("Sunil1");

list.add("anil");

list.add("Narendra");

list.add("Sunil");

System.out.println("List "+list);

}

}

package com.mkyong;

import java.util.Stack;

public class ListDemo {

public static void main(String[] args) {

Stack<String> list= new Stack<>();

list.push("Sunil1");

list.push("anil");

list.push("Narendra");

list.push("Sunil");

System.out.println("List "+list);

list.pop();

System.out.println("List "+list);

}

}