How do I check the type of a subclass?

Question

I want to check the type of a subclass in Java. Here's the pseudocode I want to achieve:

public class Brown { ... }
class Poo extends Brown { ... }
class Brownie extends Brown { ... }
...

ArrayList<Brown> brownThings = new ArrayList<Brown>();
...

for (Brown i: brownThings)
    // if i is a brownie eat
    // else dispose of

Answer 1

You can use instanceof key word

if (i instanceof Brownie ) {
    // do something
  }

That exactly checks the instance type.

Answer 2

You can use instaceof operator. For example:

if (i instanceof Brownie) {
  eat(i);
} else {
  dispose(i);
}

instaceof opertaor check if the type of an object is an instance of a class or a class that extends or implements the specified type.

You can read more in Java tutorial, operators . Also see question What is the instaceof operator used for .

Answer 3

instanceof can handle that just fine.

Answer 4

This should do:

for (Brown i: brownThings) {
    if (i instanceof Brownie) {
        //eat
    }
}