Sort a single String in Java

Question

Is there a native way to sort a String by its contents in java? E.g.

String s = \"edcba\"  ->  \"abcde\"

Answer 1

Convert to array of chars → Sort → Convert back to String:

String s = "edcba";
char[] c = s.toCharArray();        // convert to array of chars 
java.util.Arrays.sort(c);          // sort
String newString = new String(c);  // convert back to String
System.out.println(newString);     // "abcde"

Answer 2

toCharArray followed by Arrays.sort followed by a String constructor call:

import java.util.Arrays;

public class Test
{
    public static void main(String[] args)
    {
        String original = "edcba";
        char[] chars = original.toCharArray();
        Arrays.sort(chars);
        String sorted = new String(chars);
        System.out.println(sorted);
    }
}

EDIT: As tackline points out, this will fail if the string contains surrogate pairs or indeed composite characters (accent + e as separate chars) etc. At that point it gets a lot harder... hopefully you don't need this :) In addition, this is just ordering by ordinal, without taking capitalisation, accents or anything else into account.

Answer 3

Question: sort a string in java

public class SortAStringInJava {
    public static void main(String[] args) {

        String str = "Protijayi";
// Method 1
        str = str.chars() // IntStream
                .sorted().collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append).toString();

        System.out.println(str);
        // Method 2
        str = Stream.of(str.split(" ")).sorted().collect(Collectors.joining());
        System.out.println(str);
    }
}

Answer 4

    String a ="dgfa";
    char [] c = a.toCharArray();
    Arrays.sort(c);
    return new String(c);

Note that this will not work as expected if it is a mixed case String (It'll put uppercase before lowercase). You can pass a comparator to the Sort method to change that.