• List maintains elements in Particular Sequence.
• Two types of List 1.ArrayList and 2.LinkedList
• ArrayList is faster while accessing elements but slower while Insertion and Deletion
• LinkedList is slow in random access but faster during insertion and deletion

Operations in ArrayList

class Fruits
{	
  String Name = "Fruit";
}

class Apple extends Fruits
{	
 public Apple()
 {
   Name = "Apple";
 }
}

class Orange extends Fruits
{	
 public Orange()
 {
  Name = "Orange";
 }
}

class Mango extends Fruits
{	
 public Mango()
 {
  Name = "Mango";
 }
}

Adding Element – List.add()

List<Fruits> arrFruits = new ArrayList<Fruits>();
Fruits objApple  = new Apple();
Fruits objMango  = new Mango();
arrFruits.add(objApple);
arrFruits.add(objMango);

Removing Element – List.remove()

arrFruits.remove(objApple);

Removing by Index – List.remove()

arrFruits.remove(1);

Index of Element – List.indexOf()

arrFruits.indexOf(objMango);

Index of Element – List.indexOf()

arrFruits.indexOf(objMango);

SubList – List.subList(StartPOS, EndPOS)

List<Fruits> arrNewFruits = arrFruits.subList(0,2);

containsAll – NewList.containsAll(OrgList)

 arrNewFruits.containsAll(arrFruits);

set Value at Index

 arrNewFruits.set(1, new Orange());

removeAll

 arrFruits.removeAll(arrFruits);

addAll

 arrFruits.addAll(arrNewFruits);

retainAll – set Intersection Operation
retainAll performs set Interscetion Operation by taking Two ArrayList. It Retains Boolean true if intersection finds element false otherwise.

List<Integer> arrNums1 = new ArrayList<Integer>();
arrNums1.add(1);
arrNums1.add(2);
arrNums1.add(3);
		
List<Integer> arrNums2 = new ArrayList<Integer>();
arrNums2.add(1);

System.out.println(arrNums1.retainAll(arrNums2));
System.out.println(arrNums1);