CopyOnWriteArrayList iterator() method in Java

The iterator() method of CopyOnWriteArrayList returns an iterator over the elements in this list in proper sequence. The iterator does NOT support the remove method.

Syntax:

public Iterator iterator()

Parameters: The function does not accept any parameters.

Return Value: The function returns an iterator over the elements in the list.

Below programs illustrate the above function:

Program 1:

// Java Program to illustrate the CopyOnWriteArrayList
// iterator() method in Java
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.*;

public class GFG {
    public static void main(String[] args)
    {

        // create object of CopyOnWriteArrayList
        CopyOnWriteArrayList<Integer> ArrLis
            = new CopyOnWriteArrayList<Integer>();

        // Add elements
        ArrLis.add(32);
        ArrLis.add(67);
        ArrLis.add(67);
        ArrLis.add(100);

        // print CopyOnWriteArrayList
        System.out.println("CopyOnWriteArrayList: " + ArrLis);

        // Call iterator() method of
        Iterator iteratorVals = ArrLis.iterator();

        // Print elements of iterator
        // created from CopyOnWriteArrayList
        System.out.println("The iterator values"
                           + " of CopyOnWriteArrayList are:");

        // prints the elements using an iterator
        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

Output:

CopyOnWriteArrayList: [32, 67, 67, 100]
The iterator values of CopyOnWriteArrayList are:
32
67
67
100

Program 2:

// Java Program to illustrate the CopyOnWriteArrayList
// iterator() method in Java
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.*;

public class GFG {
    public static void main(String[] args)
    {

        // create object of CopyOnWriteArrayList
        CopyOnWriteArrayList<String> ArrLis
            = new CopyOnWriteArrayList<String>();

        // Add elements
        ArrLis.add("gopal");
        ArrLis.add("gfg");
        ArrLis.add("jgec");
        ArrLis.add("sudo");

        // print CopyOnWriteArrayList
        System.out.println("CopyOnWriteArrayList: " + ArrLis);

        // Call iterator() method of
        Iterator iteratorVals = ArrLis.iterator();

        // Print elements of iterator
        // created from CopyOnWriteArrayList
        System.out.println("The iterator values"
                           + " of CopyOnWriteArrayList are:");

        // prints the elements using an iterator
        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

Output:

CopyOnWriteArrayList: [gopal, gfg, jgec, sudo]
The iterator values of CopyOnWriteArrayList are:
gopal
gfg
jgec
sudo

Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CopyOnWriteArrayList.html#iterator–