Solved

Element in arraylist of arraylists

Posted on 2013-11-19
2
284 Views
Last Modified: 2013-11-19
Working in Java, how do I address a specific item in an array list of arraylists?

I have the constructor:
ArrayList<ArrayList<Integer>> testpaths = new ArrayList<ArrayList<Integer>>();

Which when I print to console:
System.out.println(testpaths + "\n");

Output after running some method() is:
[[], [1], [2], [1, 5, 3], [2, 4], [1, 5], [1, 5, 6], [1, 5, 7]]

Let's say that in that 8th item [1,5,7] - I just want the "1".

Thanks!
0
Comment
Question by:Geisrud
  • 2
2 Comments
 
LVL 14

Accepted Solution

by:
jb1dev earned 500 total points
ID: 39661102
testpaths.get(7).get(0);
0
 
LVL 14

Expert Comment

by:jb1dev
ID: 39661112
The above should work fine provided you have the generics in place, as you do in your example. If you did not have the generics in place, you would need to cast the first get() result back as an ArrayList.

E.g.
((ArrayList)testpaths.get(7)).get(0);
0

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
mysql jsp example issue 32 71
hashmap order 17 40
Java 8 to Java 6 8 33
jsp CRUD operations with and without prepared statement also hibernatge 1 29
This article is meant to give a basic understanding of how to use R Sweave as a way to merge LaTeX and R code seamlessly into one presentable document.
Introduction This article is the first of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article explains our test automation goals. Then rationale is given for the tools we use to a…
This tutorial explains how to use the VisualVM tool for the Java platform application. This video goes into detail on the Threads, Sampler, and Profiler tabs.
The viewer will learn how to clear a vector as well as how to detect empty vectors in C++.

749 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question