Write a programme to accept a word and display the alphabets in an alphabetical order.

First of all we convert the string into lower case. Now as we know, String is not a mutable, we convert the string into a StringBuffer Object. Now easily use the selection sort method on the StringBuffer object. Here we use a method setCharAt(), which is in the StringBuffer class but not in String Class.

import java.util.*;
public class AlphaSort
{
    public static void main(String []args)
    {
        Scanner sc=new Scanner(System.in);
        System.out.print("Enter A String : ");
        String str=sc.nextLine();
        str=str.toLowerCase();
        StringBuffer sb=new StringBuffer(str);
        char c;
        for(int i=0;i<sb.length();i++)
        {
            for(int j=0;j<sb.length();j++)
            {
                if(sb.charAt(i)<sb.charAt(j))
                {
                    c=sb.charAt(i);
                    sb.setCharAt(i,sb.charAt(j));
                    sb.setCharAt(j,c);
                }
            }
        }
        System.out.println(sb.toString().trim());
    }
}

Output

Enter A String : national Public school
aabcchiillnnooopstul