In this example we shall show you how to check a type identification in run time. To check a type identification in run time we have performed the following steps:
- We have created a class
A, with two methodsa1()anda2(). - We have also created a class
Bthat extendsAthat overrides the inherited method fromAclass and also has two methodsb1()andb2(). - We create a new
Aobject and a newBobject and put them in anAarray. - For both fields in the array we call the
a1()anda2()methods. SinceBclass extendsAand overrides its methods, we can call them in theBobject,
as described in the code snippet below.
package com.javacodegeeks.snippets.core;
package methodoverloading;
class A {
public void a1() {
}
public void a2() {
}
}
class B extends A {
@Override
public void a1() {
}
@Override
public void a2() {
}
public void b1() {
}
public void b2() {
}
public void b3() {
}
}
public class RunTimeTypeIdentification {
public static void main(String[] args) {
A[] x = {new A(), new B()};
x[0].a1();
x[1].a2();
// Compile time: method not found in Useful:
//x[1].b1();
((B) x[1]).b1(); // Downcast/RTTI
//((MoreUseful) x[0]).u(); // Exception thrown
}
}
This was an example of how to check a type identification in run time in Java.
