• 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

List to Map conversion

 
Ranch Hand
Posts: 32
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
How can I convert a list to a map object?
[ May 26, 2004: Message edited by: Nicolas Flammel ]
 
Bartender
Posts: 10336
Hibernate Eclipse IDE Java
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
There is no addAll(Collection) method for Map, (there is one defined in the Collection interface, but it is unsupported by the Map class) so I think you will have to iterate through the List and add each entry to the Map yourself.
 
author and iconoclast
Posts: 24207
46
Mac OS X Eclipse IDE Chrome
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Yes, Paul is right. Note that there's certainly no obvious way that such an addAll() could be implemented: what would it use for the keys?
 
Sheriff
Posts: 7023
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Moving this to the Intermediate forum...
 
Ranch Hand
Posts: 884
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
If my memory serves me well, I remember this topic has been discussed somewhere here or in Java Developers Forum...

Anyway, a map stores a key-value pair, but a list don't. So if you're to convert your list into a map, how would you want to access your contents? In short, what is the key that identifies your value in the map going to be?
 
reply
    Bookmark Topic Watch Topic
  • New Topic