List -2 (ArrayList) | Java Collections Framework (JCF) Part -4

ArrayList Class
-Uses dynamic array for storing - algorithm
-Can contain duplicate
-not syncronized (It is not Thread safe, So It is lower performance)
-Maintain order
-Random access
-Manipulation slow because a lot of shifting needs to be occurred.

ArrayList has mainly two methods
-add() - Add the elements on ArrayList
-get() - get the elements from the ArrayList

Example of Basic ArrayList (print the data with iterator) code..

import java.util.ArrayList;
import java.util.Iterator;

public class ArrayListBasic {

    public static void main(String[] args) {

        ArrayList al = new ArrayList();

        al.add("Najathi");
        al.add("Naharni");
        al.add("Nazaaha");
        al.add("Thahlan");
        al.add("Thahani");

        Iterator i = al.iterator();

        while (i.hasNext()){
            System.out.println(i.next());
        }

    }

}

Example of Basic ArrayList (print the data with iterator) code..

import java.util.ArrayList;
import java.util.Iterator;

public class ArrayListBasicFor {

    public static void main(String[] args) {

        ArrayList al = new ArrayList();

        al.add("Najathi");
        al.add("Naharni");
        al.add("Nazaaha");
        al.add("Thahlan");
        al.add("Thahani");

        for(Object obj:al){
            System.out.println(obj);
        }

    }

}

addAll - add the elements to a1 object.
remove all - it will remove a2 object same elements of a1 object also.
retain all - it will compair to object and display only common object.

import java.util.ArrayList;
import java.util.Iterator;

public class ArrayListAddAll {

    public static void main(String[] args) {

        ArrayList a1 = new ArrayList();
        ArrayList a2 = new ArrayList();

        //add the elements to a1 object
        a1.add("Najathi");
        a1.add("Naharni");
        a1.add("Nazaaha");

        //add the elements to a2 object
        a2.add("Thahlan");
        a2.add("Thahani");
        a2.add("Najathi");

        //addAll - add the elements to a1 object
        //a1.addAll(a2);

        //remove all - it will remove a2 object same elements of a1 object also.
        //a1.removeAll(a2);

        //retain all - it will compair to object and display only common object
        a1.retainAll(a2);


        Iterator i = a1.iterator();

        while(i.hasNext()){
            System.out.println(i.next());
        }

    }

}

Student's Data Array List code ( User defined object in ArrayList )..

import org.omg.PortableInterceptor.ServerRequestInfo;

import java.util.ArrayList;
import java.util.Iterator;

//User defined object in ArrayList
public class StudentArrayList {

    int rollNo;
    String name;
    int age;

    public StudentArrayList(int rollNo,String name,int age){
        this.rollNo=rollNo;
        this.name=name;
        this.age=age;
    }

}

class Simple {
    public static void main(String[] args) {
        StudentArrayList s1 = new StudentArrayList(101, "Najathi", 22);
        StudentArrayList s2 = new StudentArrayList(101, "Naharni", 21);
        StudentArrayList s3 = new StudentArrayList(101, "Nazaaha", 15);

        ArrayList al = new ArrayList();
        al.add(s1);
        al.add(s2);
        al.add(s3);

        Iterator i = al.iterator();

        while (i.hasNext()){
            StudentArrayList st = (StudentArrayList) i.next();
            System.out.println(st.name + " " + st.name+ " "+st.age);
        }

    }
}