An abstract class is a template definition of methods and variables in a specific class, or category of objects. In programming ... Implementation is done similarly in Java. For example, using the ...

Becoming popular in the early 1990s and the norm today, object-oriented programming (OOP) languages, such as C++ and Java ... "classes," and one instance of a class is an "object." For example ...

as in the following example. String s1 = new String("Hello world!"); That code will create an s1 string object and a reference variable. As noted, Java strings are immutable. Once created, a string ...