Zeek_91_ArrayListDemoMethods.java

 

/*

import java.util.*;  ---------> Means you are accessing everything from utils class.

Syntax for Array list of Integers is:   ArrayList<Integer> l1= new ArrayList();

                       

 You can use  array-list for strings and other data types also;

Some of the methods and work of ArrayList are -->

 

 l1.get(i) --> getting element at position or index i.

 

 l1.size ---> Length or Size of ArrayList.

 

 l1.add(1,13); --> Means inserting element 13 at position or index 1.

 

 l1.add(2);  --> Means adding element 2 at next position available.

 

 l1.contains(5); --> Checks whether 5 is an element in array or not.

                    If it is an element then true else false

 

 l1.indexOf(2); --> Gives us index where element 2 occurs first.

 

  l1.lastIndexOf(2); --> Gives us index where element 2 occurs last.

 

 l1.addAll(l2) --> Adding ArrayList l2 into l1.

 

 l1.removeAll(l2) ---> Removing ArrayList l2 from ArrayList l1

 

 l1.remove(1,2); --->  Removing element 2 from index or position 1.

 

 l1.clear;  ---> Erasing entire l1 elements

 */

package com.company;

import java.util.*;

public class Zeek_91_ArrayListDemoMethods {

    public static void main(String[] args) {

       

        ArrayList<Integer> l1= new ArrayList();

        ArrayList<Integer> l2= new ArrayList();

       

        l2.add(19);

        l2.add(15);

        l2.add(16);

        l2.add(17);

        l2.add(14);

       

        l1.add(7);

        l1.add(9);

        l1.add(3);

        l1.add(6);

        l1.add(5);

        l1.add(9);

       

        l1.addAll(l2); //Inserting ArrayList l2 into l1

        l1.add(0,1);   //Inserting element 1 at position 0

       

        System.out.println("Does this Array list have 2 as an element? "+ l1.contains(2) );

        System.out.println("Does this Array list have 7 as an element? "+ l1.contains(7) );

       

System.out.println("First Occuring Position(INDEX) of 9 as an element in ArrayList: "+ l1.indexOf(9) );

System.out.println("Last Occuring Position(INDEX) of 9 as an element in ArrayList: "+ l1.lastIndexOf(9) );

       

        for(int i=0;i<l1.size();i++) {

            System.out.print(l1.get(i));

            System.out.print(", ");

        }

    }

}