Sort String "13,5,8,4,2,1,9" in ascending order 1,2,4,5,8,9,13 in Java

Question

How can I sort a string "13,5,8,4,2,1,9" in ascending order, to get 1,2,4,5,8,9,13?

Answer 1

1. Split it into an array of items with String.split().
2. Convert to an array of numbers with Integer.valueOf().
3. Sort the array.
4. Concatenate it all back into a StringBuilder.

Answer 2

So you have a string containing a comma-delimited set of integers that you need to sort and then output to a string? Try split-ting the string, parse-ing the integers, sort-ing the resulting array, and then join-ing the results together

Answer 3

I would tokenize the string using StringTokenizer,
parse the values (using Integer.parseInt),
then sort the results using Arrays.sort.
Lastly, re-create the string.

Answer 4

• Split the string by commas
• Parse each substring into an integer
• Sort the resulting collection
• If you need the result to be a string (it's not clear), convert each integer back into a string and join them together with commas.

If any of those steps causes you difficulties, please be more specific.

Answer 5

This is one way to sorting.

package com.java;


import java.util.ArrayList;

import java.util.Collections;


public class b{

public static void main(String[] args) {
//create an ArrayList object

ArrayList arrayList = new ArrayList();


//Add elements to Arraylist

arrayList.add("9");
arrayList.add("3");
arrayList.add("5");
arrayList.add("2");
arrayList.add("4");

Collections.sort(arrayList);


//display elements of ArrayList

System.out.println("ArrayList elements after sorting in ascending order : ");

for(int i=0; i<arrayList.size(); i++)

System.out.println(arrayList.get(i));



}

}

Answer 6

String str = "13,5,8,4,2,1,9";
StringTokenizer tokens = new StringTokenizer(", ");
ArrayList<Integer> ints = new ArrayList<Integer>();
for(String token: tokens)
   ints.add(Integer.parseInt(token));

Collection.sort(ints);
String sortedStr = "";
for(int i = 0; i + 1 < ints.size(); ++i)
   sortedStr += ints.get(i) + ", ";
if (ints.size() > 0)
   sortedStr += ints.lastElement();

Might have some misspellings, but I think not. Also, add the appropriate imports yourself =)

Answer 7

As one liner, using Google Collections (updated with Kevin's suggestion)

Joiner.on(",").join(Ordering.natural().onResultOf(new Function<String, Integer>() {
    @Override
    public Integer apply(String from) {
        return Integer.valueOf(from);
    }
}).sortedCopy(Arrays.asList("4,2,7,9,1".split(","))));

• Split using String.split()
• Transform to Integer using a Function (anyone know if there's a constant for this one somewhere?)
• Sort using a TreeSet and natural ordering
• Join the parts and transform back to a String using Joiner

(old version)

Joiner.on(',').join(
    Sets.newTreeSet(
        Iterables.transform(
            Arrays.asList("13,5,8,4,2,1,9".split(",")),
            new Function<String, Integer>() {
                @Override
                public Integer apply(String from) {
                    return Integer.parseInt(from);
                }}))));

Answer 8

Bash is SO powerful :-)

numbers="1, 2, 9, 4, 7, 5" ; for number in $(echo "$numbers") ; do echo "$number" | tr -d ", "; done | sort | tr "\n" "," ; echo ""

Answer 9

String s = "13,5,8,4,2,1,9";
String[] arr = s.split(",");
Arrays.sort(arr, new Comparator<String>() {
   @Override public int compare(String s1, String s2) {
      return Integer.parseInt(s1) - Integer.parseInt(s2);
   }
});
s = Arrays.toString(arr).replaceAll("[\\[ \\]]", "");

This solution uses:

• java.util.Comparator
• java.util.Arrays sort and toString
• String split and replaceAll
• regular expression

Answer 10

ok you can try this one it work in all case.

package com.java;

import java.util.*;

public class cd {
public static void main(String s[]) {
Collections col; List l = sort(s);

        System.out.println("\nStrings sorted List ...");
        for(int i = 0; i < s.length; i++)
        {
              System.out.println((String)l.get(i));
        }

        int ints[] = {
                                719, 2, -22, 401, 6
                                };

        Integer in[] = new Integer[ints.length];            
        for(int i = 0; i < in.length; i++)
        {
              in[i] = new Integer(ints[i]);
        }

        l = sort(in);
        System.out.println("\nIntegers sorted List ...");

        for(int i = 0; i < in.length; i++)
        {
              System.out.println((Integer)l.get(i));
        }
}

public static List sort(Object o[])
{
        ArrayList al = new ArrayList();
        for(int i = 0; i < o.length; i++)
        al.add(i, o[i]);
        List list = Collections.synchronizedList(al);
        Collections.sort(list);
        return list;
}

}

Answer 11

An alternative using java.util.Scanner

public class SortString {
    public static void main( String [] args ) {
        // Read integers using Scanner...
        Scanner scanner = new Scanner( "13,5,8,4,2,1,9" ).useDelimiter(",");

        // Put them in a Integer list
        List<Integer> list = new ArrayList<Integer>();
        while( scanner.hasNextInt() ){
            list.add( scanner.nextInt() );
        }
        // And sort it
        Collections.sort( list );
        System.out.println( list );
    }
}