Abstract method example C# program –
- Abstract methods don’t have body, they just have method signature.
- If a class has an abstract method it should be declared abstract, the vice versa is not true, which means an abstract class doesn’t need to have an abstract method compulsory.
- If a regular class extends an abstract class, then the class must have to implement all the abstract
/*
* Abstract method example java program
*/
abstract class CompositeMath {
/*
* These are i.e.AreaofCircle(int r) and AreaofRectangle(int l,int w) are
* two abstract methods which need to be implemented in the child/derived
* class
*/
public abstract int AreaofCircle(int r);
public abstract int AreaofRectangle(int l, int w);
public void Display() {
Console.WriteLine("The return results are:");
}
}
class Mensuration : CompositeMath {
/*
* In case if we don't provide implementation to these methods then program
* will throw compilation error
*/
// implementation of first abstract method
public override int AreaofCircle(int r) {
return (int) (3.14 * r * r);
}
// implementation of 2nd abstract method
public override int AreaofRectangle(int l, int w) {
return l * w;
}
}
// client class
public class Maths {
public static void Main(String[] args) {
// passing the reference of the base class
// in order to call implemented methods
CompositeMath cm = new Mensuration();
cm.Display();
Console.WriteLine(cm.AreaofCircle(5));
Console.WriteLine(cm.AreaofRectangle(5, 6));
}
}
Output:
The return results are:
78
30