There are numerous Java versions out there, not all of which necessarily agree on everything. Herein I’m sharing my own experience.<\/p> \n
\nIn Java, an abstract class is labeled “abstract” in its definition.<\/p>\n
\npublic abstract class Bird{\n…\n}\n<\/p>\n
\nYou can’t instantiate an abstract class. Rather, an abstract class is meant to be extended to one or more non-abstract ones, which can be instantiated.\n<\/p>\n
\npublic class SongSparrow extends Bird{\n….\n}\n<\/p>\n\n
Interestingly, however, you can<\/em> use an abstract class on the left side of an instantiation, with its subclass on the right side:<\/p>\n \nBird b = new SongSparrow();\n<\/p>\n Moreover, you can use an abstract class as a formal parameter:<\/p>\n public void hearSong(Bird the_bird){\n…\n}\n<\/p>\n When hearSong is called, the actual parameter will be a subclass of Bird.<\/p>\n Source:<\/p>\n docs.oracle.com<\/a><\/p>\nJack of Oracle Tutoring by Jack and Diane,<\/a> Campbell River, BC.\n","protected":false},"excerpt":{"rendered":" Self-tutoring about Java: the tutor mentions a couple of ideas about Java abstract classes. There are numerous Java versions out there, not all of which necessarily agree on everything. Herein I’m sharing my own experience. In Java, an abstract class …<\/p>\n