Java Topics
HubJava Collections FrameworkCollections Practice ProgramsComparable vs ComparatorGenericsIteratorArrayListLinkedListStackVectorHashMapHashtableLinkedHashMapTreeMapArrayDequeDeque Double-Ended QueuePriorityQueueHashSetLinkedHashSetTreeSetAdapter PatternBuilder PatternFactory PatternMVC PatternObserver PatternSingleton PatternDynamic ProgrammingGraphHashingHeapLinked List DSAQueue DSARecursionSearching AlgorithmsSorting AlgorithmsStack DSATime ComplexityTreesException Handling Best PracticesCustom ExceptionException Hierarchyfinally BlockException Handlingthrow aur throwstry-catchBuffered StreamsByte StreamsCharacter StreamsDeserializationFile ClassJava NIO New I/OSerializationArrays in JavaArray OperationsArray Practice ProgramsArray Interview QuestionsJagged ArrayMulti-Dimensional ArraysOne Dimensional Arraybreak aur continuedo-while Loopfor Loopif-else StatementsNested Loopsswitch-case Statementwhile LoopJava Compilation ProcessJava ki FeaturesPehla Java ProgramHistory of JavaJava EditionsJava Program StructureJDK, JRE aur JVMJava Kya Hai?Immutable StringsString Class in JavaString Interview QuestionsString MethodsString Practice ProgramsStringBufferStringBuilderComments in JavaData Types in JavaIdentifiers in JavaInput & Output in JavaJava KeywordsOperators in JavaType Casting in JavaVariables in JavaJava Coding Interview QuestionsCollections Interview QuestionsCore Java Interview QuestionsJDBC Interview QuestionsMultithreading Interview QuestionsOOPs Interview QuestionsSpring Framework Interview QuestionsJava 8 Date/Time APIDefault aur Static Methods in InterfaceFunctional InterfaceLambda ExpressionMethod ReferenceOptional ClassStream APIBatch ProcessingCallableStatementJDBC ArchitectureJDBC — Java Database ConnectivityJDBC Practice ProjectsMySQL ConnectionPreparedStatementResultSetStatement InterfaceTransaction ManagementCreating ThreadsDaemon ThreadExecutor FrameworkInter-Thread CommunicationMultithreading Practice ProgramsRunnable InterfaceSynchronizationThread ClassMultithreading IntroductionThread Life CycleThread PriorityJava Cheat SheetImportant Formulas & Key ConceptsImportant Java ProgramsJava Quick RevisionAbstract ClassAbstractionAnonymous ClassClass and ObjectConstructorEncapsulationInheritanceInner ClassInterfaceMethod OverloadingMethod OverridingObject ClassObject CloningObject-Oriented Programming OOPPolymorphismstatic Keywordsuper Keywordthis KeywordWrapper ClassesArray Practice ProgramsBasic Java Practice ProgramsCollection Practice ProgramsJDBC Practice ProgramsMultithreading Practice ProgramsOOPs Practice ProgramsPlacement Coding QuestionsString Practice ProgramsBanking SystemChat ApplicationE-Commerce Backend — Spring Boot REST APIEmployee Management SystemLibrary Management SystemSpring Boot Fullstack ProjectStudent Management SystemCookies in ServletExpression Language ELGenericServletHttpServletJavaServer Pages JSPJSP TagsMVC ArchitectureHttpServletRequest & HttpServletResponseServlet IntroductionServlet Life CycleSession TrackingDependency InjectionSpring BeansSpring CoreSpring FrameworkAPI GatewaySpring Cloud Config ServerDocker DeploymentEureka Server — Service DiscoverySpring Boot CRUD ApplicationException Handling in Spring BootJWT AuthenticationREST API in Spring BootSpring SecuritySpring BootSpring Data JPAValidation in Spring Boot
Stack
Last Updated : 26 May, 2026
title: Stack in Java
Collections Framework55 words5 headingsExamples included
title: Stack in Java description: Stack data structure - LIFO
LIFO (Last In, First Out) data structure. Vector ko extend karta hai.
Create karna
java exampleWoHoTech
Stack<Integer> stack = new Stack<>();Operations
Stack<Integer> stack = new Stack<>();
// Push — top par add
stack.push(10);
stack.push(20);
stack.push(30);
// Stack: [10, 20, 30] (30 is top)
// Pop — top se remove
int top = stack.pop(); // 30 (removed)
// Peek — top dekho bina remove kiye
int peek = stack.peek(); // 20
// Empty check
stack.isEmpty(); // false
stack.empty(); // false (legacy)
// Search — 1-based index from top
stack.search(20); // 1 (top is 1)
stack.search(10); // 2
Stack Use Cases
- Undo/Redo functionality
- Browser history (back button)
- Function call stack
- Expression evaluation
- Balanced parentheses check
Modern Alternative
Deque interface use karo (ArrayDeque implementation):
java exampleWoHoTech
Deque<Integer> stack = new ArrayDeque<>();
stack.push(10); // addFirst()
stack.pop(); // removeFirst()
stack.peek(); // peekFirst()Balanced Parentheses using Stack
boolean isBalanced(String s) {
Stack<Character> stack = new Stack<>();
for (char c : s.toCharArray()) {
if (c == '(' || c == '[' || c == '{') stack.push(c);
else if (c == ')' && (stack.isEmpty() || stack.pop() != '(')) return false;
else if (c == ']' && (stack.isEmpty() || stack.pop() != '[')) return false;
else if (c == '}' && (stack.isEmpty() || stack.pop() != '{')) return false;
}
return stack.isEmpty();
}
Exam Focus
Revise definitions, diagrams, examples, and short-answer points for Stack.
Interview Use
Prepare one clear explanation, one practical example, and one common mistake for this Java topic.
Search Terms
java, java programming, core java, java master course, java notes, master, course, collections
Related Java Topics
Continue learning this concept
Collections FrameworkArrayListtitle: ArrayList in JavaCollections FrameworkLinkedListtitle: LinkedList in JavaCollections FrameworkVectortitle: Vector in JavaCollections FrameworkJava Collections Frameworktitle: Collections Framework OverviewCollections FrameworkCollections Practice Programstitle: Collections ProgramsCollections FrameworkComparable vs Comparatortitle: Comparable vs Comparator