Java Collections emptyListIterator() Method with Examples

The emptyListIterator() method of Java Collections is a method that is used to iterate the List with no elements in Java.

Syntax:

public static <T> ListIterator<T> emptyListIterator()   

Parameters: It has no parameters.

Return Type: It will return the list with empty elements.

Exceptions:

• NoSuchElementException – This will occur when the given element is not found in the given collection.

Example 1: 

Java

// Java program to run the iterator with no elements
import java.util.*;

public class GFG {

    // main method
    public static void main(String[] args)
    {
        // create an list iterator
        ListIterator<String> iterator
            = Collections.emptyListIterator();

        // get the elements which is empty
        System.out.println(iterator.hasNext());
    }
}

Output

false

Example 2:

Java

// Java program to iterate the elements with a list
// of elements. Here we will get an error
// because the list is not empty
import java.util.*;

public class GFG {
    // main method
    public static void main(String[] args)
    {
        // create an array list
        List<Integer> data = new ArrayList<Integer>();

        // add 2 elements into the array list
        data.add(100);
        data.add(200);

        // iterate the elements
        ListIterator<String> iterator
            = Collections.emptyListIterator();

          // display
        System.out.println(iterator.next());
    }
}

Output:

Exception in thread "main" java.util.NoSuchElementException
    at java.util.Collections$EmptyIterator.next(Collections.java:4191)
    at GFG.main(GFG.java:12)

Example 3:

Java program to display next index and previous index element. We can do it by using the nextIndex() method to display the next index

Syntax:

iterator.nextIndex()

To display the previous index,

Syntax:

iterator.previousIndex()

Java

// Java program to display next index
// and previous index element
import java.util.*;
public class GFG {

    // main method
    public static void main(String[] args)
    {

        // create an array list
        List<Integer> data = new ArrayList<Integer>();

        // add 2 elements into the array list
        data.add(100);
        data.add(200);

        // iterate the elements
        ListIterator<String> iterator
            = Collections.emptyListIterator();
        System.out.println(iterator.nextIndex());

        // display previous element
        System.out.println(iterator.previousIndex());
    }
}

Output

0
-1