Mega Code Archive
0150 What are Abstract Classes
<![CDATA[
You can require that certain methods be overridden by subclasses by specifying the abstract type modifier. To declare an abstract method, use this general form:
abstract type name(parameter-list);
No method body is present for abstract method.
Any class that contains one or more abstract methods must also be declared abstract.
abstract class MyAbstractClass{
abstract type name(parameter-list);
}
Here is an abstract class, followed by a class which implements its abstract method.
abstract class MyAbstractClass {
abstract void callme();
void callmetoo() {
System.out.println("This is a concrete method.");
}
}
class B extends MyAbstractClass {
void callme() {
System.out.println("B's implementation of callme.");
}
}
public class Main {
public static void main(String args[]) {
B b = new B();
b.callme();
b.callmetoo();
}
}
The output:
B's implementation of callme.
This is a concrete method.
]]>