AbsractCollection iterator() Method in Java with Examples

Last Updated : 26 Nov, 2018

The iterator() method of Java AbstractCollection is used to return an iterator of the same elements as that of the Collection. The elements are returned in random order from what was present in the Collection.

Syntax:

Iterator iterate_value = AbstractCollection.iterator();

Parameters: The function does not take any parameter.

Return Value: The method iterates over the elements of the Collection and returns the values(iterators).

Below programs illustrate the use of AbstractCollection.iterator() method:

Program 1:

// Java code to illustrate iterator()
  
import java.util.*;
import java.util.AbstractCollection;
  
public class AbstractCollectionDemo {
    public static void main(String args[])
    {
  
        // Creating an empty Collection
        AbstractCollection<String>
            abs = new TreeSet<String>();
  
        // Use add() method to add
        // elements into the Collection
        abs.add("Welcome");
        abs.add("To");
        abs.add("Geeks");
        abs.add("4");
        abs.add("Geeks");
  
        // Displaying the Collection
        System.out.println("Collection: " + abs);
  
        // Creating an iterator
        Iterator value = abs.iterator();
  
        // Displaying the values
        // after iterating through the collection
        System.out.println("The iterator values are: ");
  
        while (value.hasNext()) {
  
            System.out.println(value.next());
        }
    }
}

Output:

Collection: [4, Geeks, To, Welcome]
The iterator values are: 
4
Geeks
To
Welcome

Program 2:

// Java code to illustrate iterator()
  
import java.util.*;
import java.util.AbstractCollection;
  
public class AbstractCollectionDemo {
    public static void main(String args[])
    {
  
        // Creating an empty Collection
        AbstractCollection<String>
            abs = new ArrayList<String>();
  
        // Use add() method to add
        // elements into the Collection
        abs.add("Welcome");
        abs.add("To");
        abs.add("Geeks");
        abs.add("4");
        abs.add("Geeks");
  
        // Displaying the Collection
        System.out.println("Collection: " + abs);
  
        // Creating an iterator
        Iterator value = abs.iterator();
  
        // Displaying the values
        // after iterating through the collection
        System.out.println("The iterator values are: ");
  
        while (value.hasNext()) {
  
            System.out.println(value.next());
        }
    }
}

Output:

Collection: [Welcome, To, Geeks, 4, Geeks]
The iterator values are: 
Welcome
To
Geeks
4
Geeks

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