ArrayDeque size() Method in Java Last Updated : 10 Dec, 2018 Comments Improve Suggest changes Like Article Like Report The Java.util.ArrayDeque.size() method in Java is used to get the size of the Deque or the number of elements present in the Deque. Syntax: Array_Deque.size() Parameters: The method does not take any parameter. Return Value: The method returns the size or the number of elements present in the Deque. Below programs illustrate the Java.util.ArrayDeque.size() method: Program 1: Adding String elements into the Deque. Java // Java code to illustrate size() import java.util.*; public class ArrayDequeDemo { public static void main(String args[]) { // Creating an empty ArrayDeque Deque<String> de_que = new ArrayDeque<String>(); // Use add() method to add elements into the Deque de_que.add("Welcome"); de_que.add("To"); de_que.add("Geeks"); de_que.add("4"); de_que.add("Geeks"); // Displaying the ArrayDeque System.out.println("ArrayDeque: " + de_que); // Displaying the size of Deque System.out.println("The size is: " + de_que.size()); } } Output: ArrayDeque: [Welcome, To, Geeks, 4, Geeks] The size is: 5 Program 2: Adding Integer elements into the Deque. Java // Java code to illustrate clear() import java.util.*; public class ArrayDequeDemo { public static void main(String args[]) { // Creating an empty ArrayDeque Deque<Integer> de_que = new ArrayDeque<Integer>(); // Use add() method to add elements into the Deque de_que.add(10); de_que.add(15); de_que.add(30); // Displaying the ArrayDeque System.out.println("ArrayDeque: " + de_que); // Displaying the size of Deque System.out.println("The size is: " + de_que.size()); } } Output: ArrayDeque: [10, 15, 30] The size is: 3 Comment More infoAdvertise with us Next Article ArrayDeque clone() Method in Java chinmoy lenka Follow Improve Article Tags : Misc Java Java-Collections Java - util package Java-Functions Java-ArrayDeque +2 More Practice Tags : JavaJava-CollectionsMisc Similar Reads ArrayDeque in Java In Java, the ArrayDeque is a resizable array implementation of the Deque interface, which stands for double-ended queue. It allows elements to be added or removed from both ends efficiently. It can be used as a stack (LIFO) or a queue (FIFO).ArrayDeque grows dynamically.It generally provides faster 10 min read ArrayDeque add() Method in Java The Java.util.ArrayDeque.add(Object element) method in Java is used to add a specific element at the end of the Deque. The function is similar to the addLast() method of ArrayDeque in Java. Syntax: Array_Deque.add(Object element) Parameters: The parameter element is of the type ArrayDeque and refers 2 min read ArrayDeque addFirst() Method in Java The java.util.ArrayDeque.addFirst(Object element) method in Java is used to insert a specific element at the front of this deque. Syntax: Array_Deque.addFirst(Object element) Parameters: The parameter element is of the type ArrayDeque and refers to the element to be added. Return Value: The function 2 min read ArrayDeque addLast() Method in Java The java.util.ArrayDeque.addLast(Object element) method in Java is used to insert a specific element at the end of this deque. It is similar to the add() method in Java. Syntax: Array_Deque.addLast(Object element) Parameters: The parameter element is of the type ArrayDeque and refers to the element 2 min read ArrayDeque clear() Method in Java The Java.util.ArrayDeque.clear() method in Java is used to remove all of the elements from the Deque. Using the clear() method only clears all the element from the deque and does not delete the deque. In other words, it can be said that the clear() method is used to only empty an existing ArrayDeque 2 min read ArrayDeque size() Method in Java The Java.util.ArrayDeque.size() method in Java is used to get the size of the Deque or the number of elements present in the Deque. Syntax: Array_Deque.size() Parameters: The method does not take any parameter. Return Value: The method returns the size or the number of elements present in the Deque. 2 min read ArrayDeque clone() Method in Java The Java.util.ArrayDeque.clone() method is used to return a shallow copy of this deque. It just creates a copy of the deque. Syntax: Array_Deque.clone() Parameters: The method does not take any parameter. Return Value: The method just returns a copy of the ArrayDeque. Below programs illustrate the J 2 min read ArrayDeque contains() Method in Java The Java.util.ArrayDeque.contains() method in Java is used to check or verify whether a specific element is present in the Deque or not. Syntax: Array_Deque.contains(Object element) Parameters: The parameter element is of the type of ArrayDeque. This is the element that needs to be tested if it is p 2 min read ArrayDeque iterator() Method in Java The Java.util.ArrayDeque.iterator() method is used to return an iterator of the elements of the ArrayDeque. Syntax: Iterator iterate_value = Array_Deque.iterator(); Parameters: The method does not take any parameter. Return Value: The method iterates over the elements of the deque and returns the va 2 min read ArrayDeque descendingIterator() Method in Java The Java.util.ArrayDeque.descendingIterator() method is used to return an iterator of the same elements as the ArrayDeque but in the reverse order. Syntax: Iterator iterate_value = Array_Deque.descendingIterator(); Parameters: The method does not take any parameter. Return Value: The method iterates 2 min read Like