if (obj instanceof classVariable) ?

[natG]

Hi;

How can I check if an object is an instance of a class where the class is
represented in a Class variable?

boolean checkInstance(Object obj, Class c){
if (obj instanceof c) does NOT WORK!
}

thanks
-nat

 

[Harald Hein]

Hi;

How can I check if an object is an instance of a class where the
class is represented in a Class variable?

If you don't need inheritance

if(obj.getClass().equals(c))

 

[Skippy]

How can I check if an object is an instance of a class where the

If you don't need inheritance

if(obj.getClass().equals(c))

if(obj.getClass().toString().equals(c.toString()))

or maybe (don't know) :

if(object.getClass() == c)

 

[Rach]

Hi;

How can I check if an object is an instance of a class where the class
is represented in a Class variable?

boolean checkInstance(Object obj, Class c){
if (obj instanceof c) does NOT WORK!
}

You can only use instance of statically, if you want to dynamically check an
object is of a type of a class, then use

obj.getClass().equals(clazz);

or for inheritence,

clazz.isAssignableFrom(obj.getClass());

 

[Stefan Matthias Aust]

boolean checkInstance(Object obj, Class c){
if (obj instanceof c) does NOT WORK!
}

This should do the trick:

return c.isInstance(obj)

See
http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Class.html#isInstance(java.lang.Object)


bye

 

[Ken Sprague]

The java.lang.Class.isInstance method should work:

if (c.isInstance(obj)) {
...
}

Ken

 

[natG]

Thank you all who replied.

I should have mentioned that I need it to return true, if 'c' (the Class
parameter) is passed an Interface, and obj (the first parameter) implements it.

Therefore, I would assume that c.isInstance would do the trick.

Correct?

Thank you all,
-nat

 

[Jorn W Janneck]

if(obj.getClass().toString().equals(c.toString()))

that won't do, as two different classes might have the same class name, even
the same fully qualified one.

or maybe (don't know) :

if(object.getClass() == c)

that should work, but using equals seems more robust.

-- j

 

[Roedy Green]

boolean checkInstance(Object obj, Class c){
if (obj instanceof c) does NOT WORK!

see http://mindprod.com/jgloss/instanceof.html