• 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

Generics.

 
Ranch Hand
Posts: 664
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator


When I am changing the argument of addAnimal() from addAnimal(ArrayList<Animal> animals) to addAnimal(List<Animal> animals)
Why is the code compiling and running with out errors?

I know, in the first case its the actual object and in the second case its a reference type but I cant understand how it's making a difference.
 
Ranch Hand
Posts: 162
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hint: List is a interface, ArrayList is a class that implements List
 
Nabila Mohammad
Ranch Hand
Posts: 664
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I already know that...
How does it make a differnece....
Please be more clear..I am having a hard time figuring this topic...
 
sridhar row
Ranch Hand
Posts: 162
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
You are passing a List reference to an ArrayList. It wont work List IS-NOT-A ArrayList the other way is true. Hope the below code helps

 
Nabila Mohammad
Ranch Hand
Posts: 664
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
That makes a lot of sense...!

Thanks alot..
 
sridhar row
Ranch Hand
Posts: 162
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
you are welcome!!
 
Can you really tell me that we aren't dealing with suspicious baked goods? And then there is this tiny ad:
a bit of art, as a gift, that will fit in a stocking
https://gardener-gift.com
reply
    Bookmark Topic Watch Topic
  • New Topic