The threads can communicate with each other through wait(), notify(), and notifyAll() methods in Java. These are the final methods defined in the Object class and can be called only from within a synchronized context. The wait() method causes the current thread to wait until another thread invokes the ... Read More

In Java, an Enum is a class or special datatype that defines a collection of constants. It was introduced in Java version 1.5. When we need a predefined list of values that do not represent numeric or textual data, we can use an Enum class. Enums are constants, which means their fields ... Read More

What is a Mersenne Number? A Mersenne number is a positive integer that is obtained using the expression M(n)= 2n-1, where 'n' is an integer. If you keep any value of n (e.g., 0, 1, 2, 3) in the above expression, the result will be a Mersenne number. For example, consider ... Read More

In Java, we can compare two dates using the compareTo() method of the Comparable interface. This is a common way to compare two dates, and this method returns an integer value based on which you can specify which date occurs before, after, or if it is equal. Here are the ... Read More

The run() method of the Thread class is called internally after the start() method is invoked to begin a new thread. However, if the run() method is called directly (without start()), it does not start a separate thread and executes within the current thread. The run() Method In Java, the ... Read More

In Java, a HashMap is a subclass of the AbstractMap class and is used to store key-value pairs. Each key in the map is mapped to a single value in the map, and the keys are unique.Printing Java HashMap Elements  We can insert a key only once in a map, ... Read More

In Java, an exception is an event that occurs during the execution of a program. When an Exception occurs, the normal flow of the program is disrupted, and the program/application terminates abnormally, which is not recommended; therefore, these exceptions can be handled. What is UnsupportedOperationException in Java? An UnsupportedOperationException is ... Read More

What are Generic Collections in Java? In Java, the Generic collections were introduced in Java 5. These collections disable the type-casting, and there is no need for explicit type-casting if we use generic collections. The generic collections are type-safe and detect type-related errors at compile time. It allows the datatypes to ... Read More

In Java, Collection and Collections are important components of the Collections Framework. The Collection has various sub-interfaces such as Set, List, and Queue. The Collections provides static methods to perform various operations on collections, such as sorting, searching, and synchronization. Let's learn them one by one with proper definitions, syntax, ... Read More

What is an Annotation? An annotation is like metadata that provides additional information about the code. It does not affect the code directly but provides the information so that the compiler or runtime environment can use it while executing the code. To define or use any annotation in Java, you ... Read More