• 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
  • Tim Cooke
  • paul wheaton
  • Ron McLeod
  • Jeanne Boyarsky
Sheriffs:
  • Paul Clapham
Saloon Keepers:
  • Tim Holloway
  • Roland Mueller
Bartenders:

Generic Assignments

 
Ranch Hand
Posts: 182
Java
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator


What happens if we say
List ls4=ls1;
ls1 is of type Integer. After assigning it to ls4 , ls4 is able to hold both String and Integer. And also we are able to assign ls5=ls4.

Please explain...
 
Ranch Hand
Posts: 598
Android Eclipse IDE Ubuntu
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Yes because raw reference types allows you to add anything which is an Object.

This runs fine because all the Objects are added at runtime and generics are only for compile time.
 
Ranch Hand
Posts: 1032
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
When you use raw types you don't have any sort of compile time type safety (which is what generics provides.) When you assign l1 to l4 that's not a problem, but when you add anything to l4 you will get a compiler warning which mentions unsafe operations.
 
Ranch Hand
Posts: 124
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
It is worth noting that as of Java 5, you will get a warning if you
add *anything* to a raw type, even if there was never any generic
type involved.
 
You can't expect to wield supreme executive power just because
Clean our rivers and oceans from home
https://www.kickstarter.com/projects/paulwheaton/willow-feeders
reply
    Bookmark Topic Watch Topic
  • New Topic