Solved

How do I arrange multi-dimensional array by the String date value (MM/dd/yyyy) of the sub-arrays?

Posted on 2007-12-03
10
230 Views
Last Modified: 2013-12-14
This question is very urgent.  I'm finalizing something that needs to be done in a few hours.  While I'm tinkering with it, I figured I would post it here.

I've got an multi-dimentsional arary that would expand out as follows:

People Array {
              0 =>  Array {
                                   0 => String:"Jon Doe"
                                   1 => String:"08/21/1980"
                                   2 => String:"OtherInfo1"
                                   3 => String:"OtherInfo2"
                                   4 => String:"OtherInfo3"
                                   }
              1 =>  Array {
                                   0 => String:"Jane Doe"
                                   1 => String:"09/11/1978"
                                   2 => String:"OtherInfo1"
                                   3 => String:"OtherInfo2"
                                   4 => String:"OtherInfo3"
                                   }
              2 =>  Array {
                                   0 => String:"Billy Doe"
                                   1 => String:"05/18/1992"
                                   2 => String:"OtherInfo1"
                                   3 => String:"OtherInfo2"
                                   4 => String:"OtherInfo3"
                                   }
}

Assume the data is already verified.  How do I put the People Array in order by Date (People[x][1])?  The data is received by the user and the length the the People array is undertermined.  So I'm thinking something along the lines of loop, but just not sure one the data best way to do the conversions.

Thanks in advance for any assistance.
0
Comment
Question by:VertigoRay
  • 6
  • 4
10 Comments
 
LVL 86

Expert Comment

by:CEHJ
Comment Utility
Use Arrays.sort with a Comparator
0
 
LVL 2

Author Comment

by:VertigoRay
Comment Utility
Man I butchered the heck out of the last paragraph.  Here's a re-write:

Assume the data is already verified.  How do I put the People Array in order by Date (People[x][1])?  The data is received by the user and the length the the People array is undetermined.  So I'm thinking something along the lines of loop, but I am just not sure what the best way to do the data comparisons.

~Ray
http://www.vertigion.com
0
 
LVL 2

Author Comment

by:VertigoRay
Comment Utility
CEHJ:  Can you expand on that?   Maybe a link to an example?
0
 
LVL 2

Author Comment

by:VertigoRay
Comment Utility
Before posting this, I had already found this in the docs:
http://java.sun.com/javase/6/docs/api/java/util/Arrays.html#sort(T[],%20java.util.Comparator)

I read through it and the link to the comparator (http://java.sun.com/javase/6/docs/api/java/util/Comparator.html), but I'm still not clear on how to compare them.  That's why I posted this (phishing for an example).

Thanks again for the time!
0
 
LVL 86

Accepted Solution

by:
CEHJ earned 500 total points
Comment Utility
The fact that you're writing procedural code (as opposed to OO) makes this trickier but the following should work:
Arrays.sort(array, new Comparator() {

	DateFormat df = new SimpleDateFormat("MM/dd/yyyy");

	public int compare(Object o1, Object o2) {

		String[] s1 = (String[])o1;

		String[] s2 = (String[])o2;

		try {

			return df.parse(s1[1]).compareTo(df.parse(s2[1]);

		} catch (ParseException e) {

			e.printStackTrace();

			return Integer.MIN_VALUE;

		}

	}

});

Open in new window

0
Highfive + Dolby Voice = No More Audio Complaints!

Poor audio quality is one of the top reasons people don’t use video conferencing. Get the crispest, clearest audio powered by Dolby Voice in every meeting. Highfive and Dolby Voice deliver the best video conferencing and audio experience for every meeting and every room.

 
LVL 2

Author Comment

by:VertigoRay
Comment Utility
Forgot the closing ")" on the following line (fixed in my version:
return df.parse(s1[1]).compareTo(df.parse(s2[1]));

It is not working my particular code, but I think that it's something I need to work out.  I just need to fix a bug in my array creation which involves dynamically extending it.  I was under the impression that if I declared an array as shown below that it would dynamically expand the array as I in creased the value of the size.

The code below doesn't work ... but I was told that the logic of increasing the value of the "peopleCnt" should increase the length of the array.  The code below fails after the first pass.

Any thoughts?
int peopleCnt = 1;

String people[][];

people = new String[peopleCnt][];
 

for (<condition>)

{

   people[peopleCnt-1][0] = "<this String>";

   people[peopleCnt-1][1] = "<this String>";

   people[peopleCnt-1][2] = "<this String>";

   people[peopleCnt-1][3] = "<this String>";

   people[peopleCnt-1][4] = "<this String>";

   peopleCnt++;

}

Open in new window

0
 
LVL 2

Author Comment

by:VertigoRay
Comment Utility
Correction ... line 3:
int peopleCnt = 1;

String people[][];

people = new String[peopleCnt][5];

 

for (<condition>)

{

   people[peopleCnt-1][0] = "<this String>";

   people[peopleCnt-1][1] = "<this String>";

   people[peopleCnt-1][2] = "<this String>";

   people[peopleCnt-1][3] = "<this String>";

   people[peopleCnt-1][4] = "<this String>";

   peopleCnt++;

}

Open in new window

0
 
LVL 86

Expert Comment

by:CEHJ
Comment Utility
An array is inherently fixed size. You can't change it. You need to use a collection class if you want dynamic growth/shrinkage
0
 
LVL 2

Author Closing Comment

by:VertigoRay
Comment Utility
I'll figure out collections.  I believe I'm out of bounds on the existing question, so I'll award you the earned points.  Thank you very much for your assistance!
0
 
LVL 86

Expert Comment

by:CEHJ
Comment Utility
:-)
0

Featured Post

Find Ransomware Secrets With All-Source Analysis

Ransomware has become a major concern for organizations; its prevalence has grown due to past successes achieved by threat actors. While each ransomware variant is different, we’ve seen some common tactics and trends used among the authors of the malware.

Join & Write a Comment

Suggested Solutions

Introduction Java can be integrated with native programs using an interface called JNI(Java Native Interface). Native programs are programs which can directly run on the processor. JNI is simply a naming and calling convention so that the JVM (Java…
How to install Selenium IDE and loops for quick automated testing. Get Selenium IDE from http://seleniumhq.org (http://seleniumhq.org) Go to that link and select download selenium in the right hand columnThat will then direct you to their downlo…
Viewers will learn about arithmetic and Boolean expressions in Java and the logical operators used to create Boolean expressions. We will cover the symbols used for arithmetic expressions and define each logical operator and how to use them in Boole…
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.

762 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

Need Help in Real-Time?

Connect with top rated Experts

10 Experts available now in Live!

Get 1:1 Help Now