Cast from Object to int?

[gaztedo]

Hi there!

I'm developing a method which receives two Object parameters, and I need
to cast one of them to int. How can I do it?

public method(Object a, Object b){
this.b = (int)b; // doesn't work!
this.a = a;
}

Thanks in advance!

 

[Thomas Kellerer]

gaztedo, 20.12.2007 12:43:

Hi there!

I'm developing a method which receives two Object parameters, and I need
to cast one of them to int. How can I do it?

public method(Object a, Object b){
this.b = (int)b; // doesn't work!
this.a = a;
}

I guess the fact that your method declaration is invalid syntax is a
typing error in the email.

You cannot cast an Object to an int. If b is e.g. a Number object (e.g.
Integer or Long) you can do the following:

this.b = ((Number)b).intValue()

Btw: why don't you simple define your method as
public void method(Object o, int value)

Thomas

 

[gaztedo]

You cannot cast an Object to an int. If b is e.g. a Number object (e.g.
Integer or Long) you can do the following:

this.b = ((Number)b).intValue()

Thanks! It worked nice!

Btw: why don't you simple define your method as
public void method(Object o, int value)

I cannot do it... it's a long story

 

[Andrew Thompson]

gaztedo wrote:
...

I cannot do it... it's a long story

Fortunately this is a big discussion forum, and
a lot of people enjoy a long story.

 

[Roedy Green]

I'm developing a method which receives two Object parameters, and I need
to cast one of them to int. How can I do it?

You can't because int is not an Object. You could cast it perhaps to
Integer or to whatever the object actually was. From there you can
convert, but not cast, it to int.

See http://mindprod.com/jgloss/conversion.html

To find out what kind of animal you have:

System.out.println( obj.getClass().toString() );

 

[gaztedo]

Fortunately this is a big discussion forum, and
a lot of people enjoy a long story.

Well, not such a huge story. I'm developing a parser using Yacc, and it
requires to develop some constructors (before I said methods, sorry)
using Object as a type.

So that was the reason I had to use Object and I couldn't use Integer.

BTW I still have a lot of different errors :S

 

[Martin Gregorie]

Well, not such a huge story. I'm developing a parser using Yacc, and it
requires to develop some constructors (before I said methods, sorry)
using Object as a type.

Why use yacc with Java?

Have you looked at some of the Java equivalents, such as Coco/R?
http://www.ssw.uni-linz.ac.at/Research/Projects/Coco/