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Java Inheritance in Java Inheritance in Java Casting Instances

Posted by Dinu Comendant
Dinu Comendant
6,049 Points

((Animal) object.makeSound())

This is the first time I ever see the code to be written this way. Why do we write the whole code in parantheses? This concept wasn't explained in the previous videos.

1 Answer

Simon Coates
Simon Coates
8,481 Points
Simon Coates
Simon Coates
8,481 Points

do you mean?

((Animal) object).makeSound()

The parenthesis are used for precedence or bundling. Usually it forces a particular order of execution. But here, (Animal) object.makeSound() would probably be illegal. It would probably attempting to call makeSound before it had been told that object was an instance of Animal (and thus that a makeSound method was accessible). A quick demo of something similar:

class Main {
  public static void main(String[] args) {

    Object o = "some string";
    //o.toUpperCase(); 
    //(String) o.toUpperCase();
    ((String) o).toUpperCase();
  }
}

In the above, only the last line is valid.

Dinu Comendant
Dinu Comendant
6,049 Points

Thanks mate, it has become clearer