Deque iterator() method in Java Last Updated : 20 Jun, 2020 Comments Improve Suggest changes Like Article Like Report The iterator() method of Deque Interface returns an iterator over the elements in this deque in a proper sequence. The elements will be returned in order from first (head) to last (tail). The returned iterator is a “weakly consistent” iterator. Syntax: Iterator iterator() Parameters: This method does not accepts any parameter. Returns: This method returns an iterator over the elements in this deque in a proper sequence. Below programs illustrate iterator() method of Deque: Program 1: With the help of ArrayDeque. Java // Java Program Demonstrate iterator() // method of Deque import java.util.*; public class GFG { public static void main(String[] args) throws IllegalStateException { // create object of Deque Deque<Integer> DQ = new ArrayDeque<Integer>(); // Add numbers to end of Deque DQ.add(7855642); DQ.add(35658786); DQ.add(5278367); DQ.add(74381793); // Call iterator() method of Deque Iterator iteratorVals = DQ.iterator(); // Print elements of iterator // created from Deque System.out.println("The iterator values" + " of Deque are:"); // prints the elements using an iterator while (iteratorVals.hasNext()) { System.out.println(iteratorVals.next()); } } } Output: The iterator values of Deque are: 7855642 35658786 5278367 74381793 Program 2: With the help of LinkedList. Java // Java Program Demonstrate iterator() // method of Deque import java.util.*; public class GFG { public static void main(String[] args) throws IllegalStateException { // create object of Deque Deque<Integer> DQ = new LinkedList<Integer>(); // Add numbers to end of Deque DQ.add(7855642); DQ.add(35658786); DQ.add(5278367); DQ.add(74381793); // Call iterator() method of Deque Iterator iteratorVals = DQ.iterator(); // Print elements of iterator // created from Deque System.out.println("The iterator values" + " of Deque are:"); // prints the elements using an iterator while (iteratorVals.hasNext()) { System.out.println(iteratorVals.next()); } } } Output: The iterator values of Deque are: 7855642 35658786 5278367 74381793 Program 3: With the help of LinkedBlockingDeque. Java // Java Program Demonstrate iterator() // method of Deque import java.util.*; import java.util.concurrent.LinkedBlockingDeque; public class GFG { public static void main(String[] args) throws IllegalStateException { // create object of Deque Deque<Integer> DQ = new LinkedBlockingDeque<Integer>(); // Add numbers to end of Deque DQ.add(7855642); DQ.add(35658786); DQ.add(5278367); DQ.add(74381793); // Call iterator() method of Deque Iterator iteratorVals = DQ.iterator(); // Print elements of iterator // created from Deque System.out.println("The iterator values" + " of Deque are:"); // prints the elements using an iterator while (iteratorVals.hasNext()) { System.out.println(iteratorVals.next()); } } } Output: The iterator values of Deque are: 7855642 35658786 5278367 74381793 Program 4: With the help of ConcurrentLinkedDeque. Java // Java Program Demonstrate iterator() // method of Deque import java.util.*; import java.util.concurrent.ConcurrentLinkedDeque; public class GFG { public static void main(String[] args) throws IllegalStateException { // create object of Deque Deque<Integer> DQ = new ConcurrentLinkedDeque<Integer>(); // Add numbers to end of Deque DQ.add(7855642); DQ.add(35658786); DQ.add(5278367); DQ.add(74381793); // Call iterator() method of Deque Iterator iteratorVals = DQ.iterator(); // Print elements of iterator // created from Deque System.out.println("The iterator values" + " of Deque are:"); // prints the elements using an iterator while (iteratorVals.hasNext()) { System.out.println(iteratorVals.next()); } } } Output: The iterator values of Deque are: 7855642 35658786 5278367 74381793 Reference: https://docs.oracle.com/javase/8/docs/api/java/util/Deque.html#iterator-- Comment More infoAdvertise with us Next Article Deque iterator() method in Java gopaldave Follow Improve Article Tags : Misc Java Java - util package Java-Functions java-deque +1 More Practice Tags : JavaMisc Similar Reads Deque Interface in Java Deque Interface present in java.util package is a subtype of the queue interface. 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