instanceof

public class SimpleTest { @Test public void testInstanceOf(){ Object o = new Child(); assertTrue(o instanceof Object); assertTrue(o instanceof Parent); assertTrue(o instanceof Child); o = null; assertFalse(o instanceof Object); Child c = new Child(); assertTrue(c instanceof Object); assertTrue(c instanceof Parent); assertTrue(c instanceof Child); c = null; assertFalse(c instanceof Child); } } class Parent{ } class Child extends Parent{ }