Thread: Compare instance of a class to another

instanceof operator may be what you are looking for in the short term. Looks like it could be simplified using several different methods/patterns, the Template Pattern being the first that comes to mind, but you could use others or a combination of patterns (for example a Map valued with a class/interface that implements the behavior)

Thanks for the instancoof suggestion. By it's name, I thought it would work, but seems this is not so.

class Parent {
  public Parent() {
  }
}
class Child extends Parent {
  public Child() {
    super();
  }
}
public class MainClass {
  public static void main(String[] a) {
    Child child = new Child();
    if (child instanceof Parent) {
      System.out.println("true");
    }
  }
}

This example I found suggests that MY implementation will always be true because my test is to determine which child of the super was received. Thanks again for the input, while this did not directly solve the problem, it has placed me on the path with a light at the end.

I also found this page which may be useful to others reading this with similar questions.

You can get the name of object using reflection.

class Parent {
  public Parent() {
  }
}
class Child extends Parent {
  public Child() {
    super();
  }
}
public class MainClass {
  public static void main(String[] a) {
    Child child = new Child();
    if (child.getClass().getSimpleName().equals("Child")) {
      System.out.println("is child");
    }
    if (child.getClass().getSimpleName().equals("Parent")) {
      System.out.println("is parent");
    }
  }
}

edit: better yet, you don't even need the name. Just use the class object returned from getClass() and compare that to the class you want (you'll have to first check for null objects, by definition null means the object is every type and no type all at the same time).

class Parent {
  public Parent() {
  }
}
class Child extends Parent {
  public Child() {
    super();
  }
}
public class MainClass {
  public static void main(String[] a) {
    Child child = new Child();
    if (child.getClass() == Child.class ) {
      System.out.println("is child");
    }
    if (child.getClass() == Parent.class) {
      System.out.println("is parent");
    }
  }
}

You can only use the .class on actual type names, not variables. If you want to get the same class object from an actual object, use the getClass() method. Note that you will need to check to see if the object is null first since a method call on a null object will always fail.

// this will fail if either incommingObject or map[0][0] are null, you'll need to check for null before-hand
if(incomingObject.getClass() == map[0][0].getClass()) {