An abstract class can declare fields, constructors, and non-abstract methods in addition to or instead of abstract methods. For example, an abstract Vehicle class might declare fields describing ...

About Java Full Tutorial covers Java basics to advanced topics. Learn JVM, JRE, JDK, writing your first program, variables, data types, operators, loops, arrays, classes, objects, methods, ...

This course studies principles underlying the design of programming languages. It has four main objectives: Learning principles of programming languages: elements of programming languages; abstraction ...