Java Collections Coding Practice Problems Last Updated : 23 Jul, 2025 Comments Improve Suggest changes Like Article Like Report Java Collections provides dynamic and efficient data structures for handling and processing data. This collection of Java practice problems covers fundamental concepts of ArrayLists, LinkedLists, Stacks, Queues, Deques, PriorityQueues, HashMaps, and TreeSets, helping you master data manipulation, searching, sorting, and advanced operations. Whether you are a beginner or looking to enhance your problem-solving skills, these exercises will build a strong foundation in Java Collections.Java Collections Practice QuestionsBasic:ArrayList InsertionArrayList OperationsArrayList Iterate Front to BackAverage of an ArrayListCheck Sorted ArrayListMax and Min In ArrayListGet Smaller ElementsArrayList Separate Even OddLinkedList InsertionLinkedList TraversalStack DesignerOperations on StackQueue OperationsQueue TraversalQueue ReversalDeque ImplementationsInsertion in DequeDequeue TraversalDeque DeletionRotate Deque By KPriorityQueue Insertion - 1PriorityQueue Insertion - 2HashMap OperationsTreeSet OperationsTreeMap OperationsFill LinkedListEasy:Minimum Vertical SumMaximum Neighbours In ArrayListLinkedList Josephus CircleDelete Mid of a StackRemoving Consecutive DuplicatesRemoving Consecutive Duplicates - 2Parenthesis CheckerShopkeeper ProfitGet Min at PopQueue using Two StacksReverse First K Elements of QueueGenerate Binary NumbersK Sized Subarray MaximumOperations on PriorityQueueHashing for Pair - 1Hashing for Pair - 2Union of Arrays with DuplicatesUnique SubstringsIntersection of Arrays with DistinctDistinct SortedPrint Different Characters in Sorted MannerElected CandidateTie BreakerFrequency CountCount Non-Repeated ElementsFirst Repeating ElementSubarray with 0 SumSorted FrequencyCommon ElementsSort an ArrayListAre LinkedLists EqualMedium:Maximize Number of ToysMinimum Cost of RopesKth Largest ElementKth Smallest ElementRotate LinkedList By KThis set of practice questions covers everything from basic operations on ArrayLists and LinkedLists to more advanced topics like priority queues and hashing. Whether you're just starting out or want to sharpen your problem-solving skills, these exercises will help you get comfortable with essential data structures. Comment More infoAdvertise with us Next Article Company-wise Practice Problems S swetadash2000 Follow Improve Article Tags : Java Java-Collections Practice Questions Practice Tags : JavaJava-Collections Similar Reads Interview PreparationInterview Preparation For Software DevelopersMust Coding Questions - Company-wise Must Do Coding Questions - Topic-wiseCompany-wise Practice ProblemsCompany PreparationCompetitive ProgrammingSoftware Design-PatternsCompany-wise Interview ExperienceExperienced - Interview ExperiencesInternship - Interview ExperiencesPractice @GeeksforgeeksProblem of the DayTopic-wise PracticeDifficulty Level - SchoolDifficulty Level - BasicDifficulty Level - EasyDifficulty Level - MediumDifficulty Level - HardLeaderboard !!Explore More...Data StructuresArraysLinked ListStackQueueBinary TreeBinary Search TreeHeapHashingGraphAdvance Data StructuresMatrixStringAll Data StructuresAlgorithmsAnalysis of AlgorithmsSearching AlgorithmsSorting AlgorithmsPattern SearchingGeometric AlgorithmsMathematical AlgorithmsRandomized AlgorithmsGreedy AlgorithmsDynamic ProgrammingDivide & ConquerBacktrackingBranch & BoundAll AlgorithmsProgramming LanguagesCC++JavaPythonC#Go LangSQLPHPScalaPerlKotlinWeb TechnologiesHTMLCSSJavaScriptBootstrapTailwind CSSAngularJSReactJSjQueryNodeJSPHPWeb DesignWeb BrowserFile FormatsComputer Science SubjectsOperating SystemsDBMSComputer NetworkComputer Organization & ArchitectureTOCCompiler DesignDigital Elec. & Logic DesignSoftware EngineeringEngineering MathematicsData Science & MLComplete Data Science CourseData Science TutorialMachine Learning TutorialDeep Learning TutorialNLP TutorialMachine Learning ProjectsData Analysis TutorialTutorial LibraryPython TutorialDjango TutorialPandas TutorialKivy TutorialTkinter TutorialOpenCV TutorialSelenium TutorialGATE CSGATE CS NotesGate CornerPrevious Year GATE PapersLast Minute Notes (LMNs)Important Topic For GATE CSGATE CoursePrevious Year Paper: CS exams Like