Java / Set and its implementations

How do I update an existing object at HashSet in Java?

Set rejects duplicates via equals and hashCode. Changing a mutable element after insert can corrupt a HashSet; prefer immutable keys.

Perform remove before adding the element into the HashSet.

 if(!myHashSet.add(myObject)) {
     myHashSet.remove(myObject);
     myHashSet.add(myObject);
 }

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Map and its implementations

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OOPS Concepts and its implementation in Java 19 Inheritance 29 JDK, JRE, JVM, JIT Java Identifiers 4 Object, Class and Package 44 Variable 9 Instance Variables (Non Static Variables) 3 Class Variables (Static Variables) 13 Local Variables 6 Package 10 Operators 9 Data types 10 Methods 39 Modifiers 29 Control Statements 14 Access Modifiers 5 Constructor 38 Interface 46 Abstract Class 19 Enum 20 Arrays 20 Strings 32 Using String 29 Exception Collections List and its implementations 22 Set and its implementations 23 Map and its implementations 39 Queue and its implementations 4 Regular expressions 3 Design Patterns Generics 20 Casting 5 volatile 13 Java ThreadLocal 10 Java Multithreading Java Multithreading part II 18 final keyword 13 static keyword 16 Java Transactions (JTA) 21 Concurrent collections 55 Java Serialization 36 JDBC 53 JNDI 17 RMI 6 JAXB 10 JMS 45 Servlet Interview Questions 16 JMX 9 log4j 19 Annotations 10 XML 14 Garbage collection 31 Programs 8 JVM 4 Java8 streams 34 JavaFX 6 Autosys Interview questions 21 The Java Virtual Machine: How and What Is It Used For? Java 11 10 Java 12 5 Top Errors You Should Avoid when Studying Programming Java 17 1 JPMS 6 Java Record Keyword 4 MapStruct Java Interview questions Java 21 Interview Questions 46 Lombok Interview questions 48 Quarkus Interview questions 50 Micronaut Interview questions 50 Java Concurrency and Multi Threading in Java 17 and Java 21 Interview questions 50 MapStruct Java Interview questions part 2 50 Java 17 Garbage Collection Interview Questions 50 GraalVM Interview questions 50 Java 21 Coding Standards Interview Questions 50 Java 21 Virtual Threads Interview questions Java 21 Collection Framework features Interview questions 50 JVM Architecture (Java21) Interview questions 50

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