Question

Using java, create a class called MyString that has one String called word as its attribute and the following methods:
Constructor that accepts a String argument and sets the attribute.

Method permute that returns a permuted version of word. For this method, exchange random pairs of letters in the String. To get a good permutation, if the length of the String is n, then perform 2n swaps.

Use this in an application called Jumble that prompts the user for a word and the required number of jumbled versions and prints the jumbled words. For example,
Enter the word: mixed
Enter the number of jumbled versions required: 10

xdmei
eidmx
miexd
emdxi
idexm
demix
xdemi
ixdme
eximd
xemdi
xdeim

Notes:
1. It is tricky to swap two characters in a String. One way to accomplish this is to convert your String into an array of characters, swapping the characters in the array, converting it back to a String and returning it.
char[] chars = word.toCharArray(); will convert a String word to a char array chars.
String result = new String(chars); converts a char array chars into a String.

Answer 1

Here is the completed code for this problem. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. Thanks

//MyString.java class

public class MyString {

      // word

      private String word;

      // constructor accepting a word

      public MyString(String word) {

            this.word = word;

      }

      // method that returns a random permutation

      public String permute() {

            // converting word to array

            char arr[] = word.toCharArray();

            // looping for arr.length/2 number of times

            for (int i = 0; i < arr.length / 2; i++) {

                  // generating two random indices between 0 and arr.length-1

                  int randIndex1 = (int) (Math.random() * arr.length);

                  int randIndex2 = (int) (Math.random() * arr.length);

                  // swapping elements at these indices

                  char c = arr[randIndex1];

                  arr[randIndex1] = arr[randIndex2];

                  arr[randIndex2] = c;

            }

            //converting array back to String and returning it

            return new String(arr);

      }

}

//Jumble.java file

import java.util.Scanner;

public class Jumble {

      public static void main(String[] args) {

            // setting up a Scanner

            Scanner scanner = new Scanner(System.in);

            // asking and reading word

            System.out.print("Enter the word: ");

            String word = scanner.next();

            // creating a MyString object using word

            MyString myString = new MyString(word);

            // asking and reading an integer

            System.out.print("Enter the number of jumbled versions required: ");

            int n = scanner.nextInt();

            // looping for n times

            for (int i = 0; i < n; i++) {

                  // finding a permutation and printing it

                  System.out.println(myString.permute());

            }

      }

}

/*OUTPUT*/

Enter the word: amazing

Enter the number of jumbled versions required: 10

mganiza

amziagn

amiznag

ngazaim

anazigm

gmaznai

imanagz

azanimg

aiazmng

zmagani