sorting string arrays alphabetically

i allready know string arrays can be sorted alphabetically using the bubble sort and other sorting methods. i was just wondering if there is a class out-there somewhere that allows this, or something that is build into java that lets me do this with ease without using the old school sorting ways...

thanks

lance

You can use the TreeSet to store your strings (in a sorted manner).

- petter

Check this out:

http://java.sun.com/j2se/1.5.0/docs/...omparable.html
http://java.sun.com/j2se/1.5.0/docs/...omparator.html

Quote:

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Originally Posted by riscoh

Check this out:

http://java.sun.com/j2se/1.5.0/docs/...omparable.html
http://java.sun.com/j2se/1.5.0/docs/...omparator.html

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so the compair makes your strings into a int so they can be sorted or something like that?

java.util.Collections.sort

Quote:

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Originally Posted by Joe Nellis

java.util.Collections.sort

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ok i got it .. here is a example..

Code:

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import java.io.*;
import java.util.*;

public  class bubbleSort
{
        public static void main(String [] args)throws IOException
        {
                String [] stringArray = new String[20];
                int count = 8;

                stringArray[0] = "z";
                stringArray[1] = "d";
                stringArray[2] = "b";
                stringArray[3] = "a";
                stringArray[4] = "g";
                stringArray[5] = "m";
                stringArray[6] = "p";
                stringArray[7] = "i";
       
                sortArray(count, stringArray);

                System.out.println("---final---");
                for(int i = 0; i < count; i++)
                        System.out.print(stringArray[i] + "  ");

                System.out.println();

        }


        private static void sortArray(int numberofItems,
                                                                  String list[])
        {
                boolean exchangeMade;
                int pass = 0;
                String temp;

                exchangeMade = true;

                while((pass < numberofItems - 1) && exchangeMade == true)
                {
                        exchangeMade = false;
                        pass++;
                        for(int index = 0; index < (numberofItems - pass); index++)
                        {
                                System.out.println();
                                if(list[index].compareTo(list[index + 1]) > 0)
                                {
                                        temp = list[index];
                                        list[index] = list[index + 1];
                                        list[index + 1] = temp;
                                        exchangeMade = true;
                                }
                                for(int i = 0; i < 8; i++)
                                        System.out.print(list[i] + " ");
                               
                        }
                }

        }
}

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there is nothing simpler like

stringArray.sortAlpha()

or something like that?... unless i put this in a class

Quote:

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there is nothing simpler like

stringArray.sortAlpha()

or something like that?...

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Looking at your code you don't use java.util.Collections.sort(...) at all.

- petter

If you read String documentation you would see it overides the Comparable interface. This implies that the String object has a natural ordering. The ordering is lexographic (alphabetical more or less). Only objects that have a 'natural ordering' can be sorted OR you can provide a an anonymouse inner Comparable class to sort however you wish, overriding the objects natural ordering. Someone or I can give an example later.

Here is an example of sorting string (in an ArrayList>

Code:

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java.util.ArrayList<String> pList = new java.util.ArrayList<String>();
       
// add elements to list
pList.add("d");
pList.add("a");
pList.add("c");
pList.add("b");

// iterate through list
for (String str : pList)
    System.out.println(str);
       
// sort list
java.util.Collections.sort(pList);
       
// iterate through list
for (String str : pList)
    System.out.println(str);

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- petter

The sort method also takes a comparator which you can specify to pull an ordering out of the list. This creates and inline implementation of the Comparator interface

Code:

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// sort list
java.util.Collections.sort(pList, new Comparator<String>(){

  //override the compare method
  public int compare(String dis, String dat){
      // order by string length
      return dis.length() - dat.length();
  }

});  // note brace, paranthesis closure. This ends the sort method call.

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