• Post Reply Bookmark Topic Watch Topic
  • New Topic

Object[][] or some other data structure??  RSS feed

 
Ranch Hand
Posts: 231
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Friends,
I have classes(A,B..G) and roll numbers.I want to iterate through the data and put them into appropriate classes.Which data structure should i use??because I dont know before hand how many roll numbers might go into a class.I am trying to use a Object array like this:

Oject[][] arr = new Object[7][];

But the problem is I have to specify a "col" dimension,which i dont know and specifying something big impacts the performance.I dont think i can dynamically assign object like this:

Object[0][0] = new Object();
Object[0][1] = new Object();
........
Object[1][0] = new Object();

Or can I?Please help me on this friends.
 
author & internet detective
Sheriff
Posts: 37811
582
Eclipse IDE Java VI Editor
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Jas,
Welcome to JavaRanch!

It sounds like you know there are seven classes, but don't know how may roll numbers there are. So you are correct that you need an array of something. The second level should be a data structure that can grow as needed, like an ArrayList. So now you have:
ArrayList[] arr = new ArrayList[7];
 
You can't expect to wield supreme executive power just because
ScroogeXHTML 7.1 - RTF to HTML5 / XHTML converter
https://coderanch.com/t/690611/ScroogeXHTML-RTF-HTML-XHTML-converter
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!