core java in java questions asked in companies

This deals with concurrent programming. The wait() and notify() methods are designed to provide a mechanism to allow a thread to be block until a specific condition is met. However, java.util.concurrent should be used instead of wait() and notify() to reduce complexity. The wait/notify mechanism in Java is a part of the synchronization features provided … Read more

java.util.Comparator and java.lang.Comparable java.util.Comparator compares some other class’s instances, while java.lang.Comparable compares itself with another object. In Java, the Comparator and Comparable interfaces are both related to sorting objects, but they serve different purposes: Comparable Interface: The Comparable interface is used for natural ordering of objects. If a class implements the Comparable interface, it means … Read more

Equals is intended to check logical equality and == checks if both references point to same object. (Thanks Sandeep) a == b;// Compares references, not values. a.equals(b);// Compares values for equality. In Core Java, the difference between equals() and == lies in their functionality and what they compare: equals() method: equals() is a method defined … Read more

Java Development Kit (JDK) is the most widely used Java Software Development Kit. Java Runtime Environment (JRE) is an implementation of the Java Virtual Machine which executes Java programs. In Java development, JDK (Java Development Kit) and JRE (Java Runtime Environment) are two essential components, and they serve distinct purposes: JDK (Java Development Kit): Definition: … Read more

Serialization is the conversion of an object to a series of bytes, so that the object can be easily saved to persistent storage or streamed across a communication link. The byte stream can then be deserialised – converted into a replica of the original object. In Core Java, serialization refers to the process of converting … Read more