OnJava8-Examples/typeinfo/FamilyVsExactType.java
2016-12-30 17:23:13 -08:00

63 lines
1.9 KiB
Java

// typeinfo/FamilyVsExactType.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// The difference between instanceof and class
// {java typeinfo.FamilyVsExactType}
package typeinfo;
class Base {}
class Derived extends Base {}
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());
}
}
/* 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
*/