BlockingDeque peek() method in Java with examples Last Updated : 12 Jul, 2025 Comments Improve Suggest changes Like Article Like Report The peek() method of BlockingDeque returns the front element in the Deque container. It returns null if the container is empty. Syntax: public E peek() Parameters: This method does not accept any parameters. Returns: This method returns front element in the Deque container if the container is not empty. It returns false if the container is empty. Note: The peek() method of BlockingDeque has been inherited from the LinkedBlockingDeque class in Java. Below programs illustrate peek() method of BlockingDeque: Program 1: Java // Java Program Demonstrate peek() // method of BlockingDeque import java.util.concurrent.LinkedBlockingDeque; import java.util.concurrent.BlockingDeque; import java.util.*; public class GFG { public static void main(String[] args) { // create object of BlockingDeque BlockingDeque<Integer> BD = new LinkedBlockingDeque<Integer>(); // Add numbers to end of BlockingDeque BD.add(7855642); BD.add(35658786); BD.add(5278367); BD.add(74381793); // Print the queue System.out.println("Linked Blocking Deque: " + BD); System.out.println("Front element in Deque: " + BD.peek()); } } Output: Linked Blocking Deque: [7855642, 35658786, 5278367, 74381793] Front element in Deque: 7855642 Program 2: Java // Java Program Demonstrate peek() // method of BlockingDeque // when Deque is empty import java.util.concurrent.LinkedBlockingDeque; import java.util.concurrent.BlockingDeque; import java.util.*; public class GFG { public static void main(String[] args) { // create object of BlockingDeque BlockingDeque<Integer> BD = new LinkedBlockingDeque<Integer>(); // Add numbers to end of BlockingDeque BD.add(7855642); BD.add(35658786); BD.add(5278367); BD.add(74381793); // Print the queue System.out.println("Blocking Deque: " + BD); // empty deque BD.clear(); System.out.println("Front element in Deque: " + BD.peek()); } } Output: Blocking Deque: [7855642, 35658786, 5278367, 74381793] Front element in Deque: null Reference: https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/BlockingDeque.html#peek() Comment More infoAdvertise with us G gopaldave Follow Improve Article Tags : Java Java-Collections Java-Functions java-interfaces Practice Tags : JavaJava-Collections Explore BasicsIntroduction to Java4 min readJava Programming Basics9 min readJava Methods7 min readAccess Modifiers in Java6 min readArrays in Java9 min readJava Strings8 min readRegular Expressions in Java7 min readOOPs & InterfacesClasses and Objects in Java10 min readJava Constructors10 min readJava OOP(Object Oriented Programming) Concepts10 min readJava Packages7 min readJava Interface11 min readCollectionsCollections in Java12 min readCollections Class in Java13 min readCollection Interface in Java6 min readIterator in Java5 min readJava Comparator Interface6 min readException HandlingJava Exception Handling8 min readJava Try Catch Block4 min readJava final, finally and finalize4 min readChained Exceptions in Java3 min readNull Pointer Exception in Java5 min readException Handling with Method Overriding in Java4 min readJava AdvancedJava Multithreading Tutorial15+ min readSynchronization in Java10 min readFile Handling in Java5 min readJava Method References9 min readJava 8 Stream Tutorial15+ min readJava Networking15+ min readJDBC Tutorial12 min readJava Memory Management4 min readGarbage Collection in Java6 min readMemory Leaks in Java3 min readPractice JavaJava Interview Questions and Answers15+ min readJava Programs - Java Programming Examples8 min readJava Exercises - Basic to Advanced Java Practice Programs with Solutions7 min readJava Quiz | Level Up Your Java Skills1 min readTop 50 Java Project Ideas For Beginners and Advanced [Update 2025]15+ min read Like