• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Jeanne Boyarsky
  • Ron McLeod
  • Paul Clapham
  • Liutauras Vilda
Sheriffs:
  • paul wheaton
  • Rob Spoor
  • Devaka Cooray
Saloon Keepers:
  • Stephan van Hulst
  • Tim Holloway
  • Carey Brown
  • Frits Walraven
  • Tim Moores
Bartenders:
  • Mikalai Zaikin

another instanceof question

 
Greenhorn
Posts: 10
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi all, for the following codes:


class Fruit{}
class Apple extends Fruit{}
class Orange extends Fruit{}

public class Over
{
public static void main(String [] arg)
{
Apple a=new Apple(); // 1
//Fruit a=new Apple(); //2
System.out.println ( a instanceof Orange) ;

}
}



I would get an compile error where I expected to be false.
If I comment the line 1 and uncomment line 2, I would get the result.
Why is it?
 
Ranch Hand
Posts: 1704
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
You can declare same variable name(a) twice, if you declare you will get compilation error.
 
Ranch Hand
Posts: 66
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Because Class Apple is not in the same class hierarchy line as Orange.

let me know if i am wrong
 
I child proofed my house but they still get in. Distract them with this tiny ad:
a bit of art, as a gift, the permaculture playing cards
https://gardener-gift.com
reply
    Bookmark Topic Watch Topic
  • New Topic