Javarevisited

Hello guys, I have an interesting news to share with you today. After a long wait of almost 10 years, the  Effective Java 3rd edition is f...

>Hello guys, if you are learning Java or want to learn Java but not sure if CodeGym is the right place for you or not then you have come...

PriorityQueue is an unbounded Queue implementation in Java, which is based on a priority heap. PriorityQueue allows you to keep elements...

What is EnumMap in Java EnumMap in Java is added on JDK   5 release along with other important features like   Autoboxing , varargs , an...

CopyOnWriteArraySet is little brother of CopyOnWriteArrayList class. These are special purpose collection classes which was added on JDK 1....

Sometimes, we need to merge multiple lists into one before performing any operation, say Iteration or transformation. It's quite commo...

Read-only List , Map and Set in Java A read-only List means a List where you can not perform modification operations like add , remove...

ConcurrentHashMap in Java is introduced as an alternative of Hashtable in Java 1.5 as part of the Java concurrency package. Prior to Java ...

EnumSet is one of the specialized implementations of the Set interface for an enumeration type, introduced in Java 1.5 along with the enume...

Though both Iterator and Enumeration allows you to traverse over elements of Collections in Java, there is some significant difference bet...

Hello guys, if you are looking for an answer of popular Java interview question, how HashMap works in Java? or How HashMap works internally ...

The difference between fail-safe and fail-fast Iterator is becoming favorite core java interview questions day by day, the reason it  tou...

What is the difference between List and Set in Java is a very popular Java collection interview question and an important fundamental ...

ArrayList and Vector are two of the most used classes on the java collection package and the difference between Vector and ArrayList is o...

HashMap vs Hashtable in Java Though both Hashtable and HashMap are data-structure based upon hashing and implementation of Map interface,...

LinkedList and ArrayList both implement List Interface but how they work internally is where the differences lie. The main  difference be...

TreeSet , LinkedHashSet, and HashSet all are implementation of the  Set interface and by virtue of that, they follow the contract of Se...

Synchronized vs Concurrent Collections Though both Synchronized and Concurrent Collection classes provide thread-safety, the differences b...

The Java collection framework offers implementation of different data structure like an array, list, set, map, queue, tree, etc and the...

It's not easy to get key from the value in Hashtable or HashMap, as compared to getting value from key because HashMap or Hashtable d...