FamilyVsExactType.java

package com.brianway.learning.java.base.typeinfo;

/**
 * The difference between instanceof and class.
 */
public class FamilyVsExactType {
    static void test(Object x) {
        System.out.println("Testing x of type " + x.getClass());
        System.out.println("x instanceof Base " + (x instanceof Base));
        System.out.println("x instanceof Derived " + (x instanceof Derived));
        System.out.println("Base.isInstance(x) " + Base.class.isInstance(x));
        System.out.println("Derived.isInstance(x) "
                + Derived.class.isInstance(x));
        System.out.println("x.getClass() == Base.class "
                + (x.getClass() == Base.class));
        System.out.println("x.getClass() == Derived.class "
                + (x.getClass() == Derived.class));
        System.out.println("x.getClass().equals(Base.class)) "
                + (x.getClass().equals(Base.class)));
        System.out.println("x.getClass().equals(Derived.class)) "
                + (x.getClass().equals(Derived.class)));
    }

    public static void main(String[] args) {
        test(new Base());
        test(new Derived());
    }
}

class Base {
}

class Derived extends Base {
}
/* Output:
Testing x of type class typeinfo.Base
x instanceof Base true
x instanceof Derived false
Base.isInstance(x) true
Derived.isInstance(x) false
x.getClass() == Base.class true
x.getClass() == Derived.class false
x.getClass().equals(Base.class)) true
x.getClass().equals(Derived.class)) false
Testing x of type class typeinfo.Derived
x instanceof Base true
x instanceof Derived true
Base.isInstance(x) true
Derived.isInstance(x) true
x.getClass() == Base.class false
x.getClass() == Derived.class true
x.getClass().equals(Base.class)) false
x.getClass().equals(Derived.class)) true
*///:~