how to sort a string alphabetically java [closed]

Question 1

You can do this using Arrays.sort, if you put the characters into an array first. (It must be an array of Character objects rather than char primitives, in order to use a custom case-insensitive comparator.)

// put the characters into an array
Character[] chars = new Character[str.length()];
for (int i = 0; i < chars.length; i++)
    chars[i] = str.charAt(i);

// sort the array
Arrays.sort(chars, new Comparator<Character>() {
    public int compare(Character c1, Character c2) {
        int cmp = Character.compare(
            Character.toLowerCase(c1.charValue()),
            Character.toLowerCase(c2.charValue())
        );
        if (cmp != 0) return cmp;
        return Character.compare(c1.charValue(), c2.charValue());
    }
});

// rebuild the string
StringBuilder sb = new StringBuilder(chars.length);
for (char c : chars) sb.append(c);
str = sb.toString();

Question 2

You may try to look for Collections.sort and then try like this:-

Collections.sort(caps, String.CASE_INSENSITIVE_ORDER);

Something like this:-

private static Comparator<String> ALPHA_ORDER = new Comparator<String>() {
    public int compare(String str1, String str2) {
        int x = String.CASE_INSENSITIVE_ORDER.compare(str1, str2);
        if (x== 0) {
            x= str1.compareTo(str2);
        }
        return x;
    }
};

Collections.sort(list, ALPHA_ORDER);

EDIT:-

For sorting alphabetically in a string try like this:-

Collator col = Collator.getInstance(new Locale("en", "EN"));
String s = "AbaC";
String[] s1= s.split("");
Arrays.sort(s1, col);
String sorted = "";
for (int i = 0; i < s1.length; i++)
{
  sorted += s1[i];
}
System.out.println(sorted);

Question 3

Turn the String into a character array, then compare the int values of each character in your sort.

Methods needed: String.toCharArray();