What is the difference between JDK, JRE and JVM in Java?

Related Java interview questions

• What is the difference between == and equals() in Java?

  == compares primitives by value and objects by reference (whether they are the exact same object), while equals() compares the logical content of two objects when the class overrides it.

• What is the difference between String, StringBuilder and StringBuffer in Java?

  String is immutable, StringBuilder is a mutable and fast but not thread-safe buffer, and StringBuffer is a mutable buffer with synchronized methods that is thread-safe but slower.

• What is the difference between final, finally and finalize in Java?

  final is a keyword that prevents reassigning a variable, overriding a method or extending a class; finally is a block that always runs after try/catch for cleanup; finalize() was a method called by the garbage collector and is now deprecated.

• What is the difference between an abstract class and an interface in Java?

  An abstract class can have instance fields, constructors and a mix of implemented and abstract methods but supports only single inheritance, while an interface defines a contract that a class can implement multiple times and, since Java 8, can include default methods.