Dynamic dispatch is a process of selecting, which methods to call at run-time. It is a mechanism by which a call to overridden method at run time is resolved rather then compile time.
Dynamic method dispatch
Dynamic dispatch is a process of selecting, which methods to call at run-time. It is a mechanism by which a call to overridden method at run time is resolved rather then compile time. Method of execution is based upon the type of object being referred. By this run-time polymorphism is achieved in java. Let suppose a class A contain a method display() ,class B extends A and override method display, we generally create a object of parent class or child class or reference variable of parent class. Now we are creating a reference of parent class through which we call parent class method and child class method as well.
Example : How to implement dynamic dispatch in java
class A
{
public void display()
{
System.out.println("In class A");
}
}
class B extends A
{
public void display()
{
System.out.println("In class B");
}
}
public class Dynamicdispatch
{
public static void main(String args[])
{
A ob=new A();
B ob2=new B();
A r; //obtain a reference of type A
r=ob; //r refer to A object
r.display(); //call display() method of A
r=ob2; //r refer to b object
r.display(); //call display() method of B
System.out.println("In main Class");
}
}Description : In the above example we are creating a reference of class A and through the reference of parent class that is A we used to refer the child class methods. and also parent class methods.
Output : After compiling and executing the above program
