What is the use of inheritance injava but I dont understand how it is inheritance

Question

class Teacher
{
String designation = "Teacher";
String collegeName = "Beginnersbook";
void does()
{
System.out.println("Teaching");
} }
public class PhysicsTeacher extendsTeacher
{
String mainSubject = "Physics";
public static void main(String args[])
{
PhysicsTeacher obj = new PhysicsTeacher(); System.out.println(obj.collegeName); System.out.println(obj.designation); System.out.println(obj.mainSubject);
obj.does();
} }

Answer 1

The main point is that you want to write things only once (DRY = don't repeat yourself!). When your program deals with different teachers, you would have a lot of similar objects. It is smart to store their common traits in only one point of the program. This is what you do with using a class Teacher, which you use as a template when you use extends while you define different types of teachers. hope it helps.