Question

Please convert this code written in Python to Java:

import string
import random

#function to add letters
def add_letters(number,phrase):
   #variable to store encoded word
   encode = ""
  
   #for each letter in phrase
   for s in phrase:
       #adding each letter to encode
       encode = encode + s
       for i in range(number):
           #adding specified number of random letters adding to encode
           encode = encode + random.choice(string.ascii_letters)
   #returns encoded word
   return encode
#function to remove letters
def remove_letters(number,phrase):
   #variable to store decoded word
   decode = ""
  
   #iterating each letter in phrase
   for i in range(len(phrase)):
       #if i % number + 1 is zero
       if i % (number + 1) == 0:
           #adding letters in specified position to decode
           decode = decode + phrase[i]
   #returns decoded word
   return decode

#repeat until user wants to quit
while True:
   print("")
   #prompt for user option
   userOption = input("(e)ncode, (d)ecode, (q)uit: ")
  
   #if option is encode
   if userOption == "e":
       #prompt for number
       number = int(input("Enter a number between 1 and 5: "))
      
       #repeat until number is valid
       while True:
           #if number is valid
           if number >= 1 and number <= 5:
               break
           #if number is not valid
           else:
               print("Try Again...")
              
               #prompt for number
               number = int(input("Enter a number between 1 and 5: "))
      
       #prompt for phrase to encode
       phrase = input("Enter a phrase to encode: ")
      
       #calling function add_letters and printing encoded word
       print("Your encoded word is: "+add_letters(number,phrase))
  
   #if option is decode
   elif userOption == "d":
       #prompt for number
       number = int(input("Enter a number between 1 and 5: "))
      
       #repeat until number is valid
       while True:
           #if number is valid
           if number >= 1 and number <= 5:
               break
           #if number is not valid
           else:
               print("Try Again...")
              
               #prompt for number
               number = int(input("Enter a number between 1 and 5: "))
      
       #prompt for phrase to decode
       phrase = input("Enter a phrase to decode: ")
      
       #calling function remove_letters and printing decoded word
       print("Your decoded word is: "+remove_letters(number,phrase))
      
   #if option is quit
   elif userOption == "q":
       break
      
   #if option is wrong option
   else:
       print("Try Again...")

Answer 1

Here is the converted code for this problem in Java. 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

// EncodeDecode.java

import java.util.Scanner;

public class EncodeDecode {

      // function to add letters

      static String add_letters(int number, String phrase) {

            // variable to store encoded word

            String encode = "";

            // variable to store all letters in ascii table

            String letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

            // for each letter in phrase

            for (Character c : phrase.toCharArray()) {

                  // adding each letter to encode

                  encode = encode + c;

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

                        // adding specified number of random letters adding to encode

                        encode = encode

                                    + letters.charAt((int) (Math.random() * letters

                                                 .length()));

                  }

            }

            // returns encoded word

            return encode;

      }

      // function to remove letters

      static String remove_letters(int number, String phrase) {

            // variable to store decoded word

            String decode = "";

            // iterating each letter in phrase

            for (int i = 0; i < phrase.length(); i++)

                  // if i % number + 1 is zero

                  if (i % (number + 1) == 0) {

                        // adding letters in specified position to decode

                        decode = decode + phrase.charAt(i);

                  }

            // returns decoded word

            return decode;

      }

      public static void main(String[] args) {

            Scanner scanner = new Scanner(System.in);

            // repeat until user wants to quit

            while (true) {

                  System.out.println("\n(e)ncode, (d)ecode, (q)uit: ");

                  // prompt for user option

                  char userOption = scanner.nextLine().toLowerCase().charAt(0);

                  // if option is encode

                  if (userOption == 'e') {

                        // prompt for number

                        System.out.print("Enter a number between 1 and 5: ");

                        int number = Integer.parseInt(scanner.nextLine());

                        // repeat until number is valid

                        while (true) {

                              // if number is valid

                              if (number >= 1 && number <= 5) {

                                    break;

                              }

                              // if number is not valid

                              else {

                                    System.out.println("Try Again...");

                                    // prompt for number

                                    System.out.print("Enter a number between 1 and 5: ");

                                    number = Integer.parseInt(scanner.nextLine());

                              }

                        }

                        // prompt for phrase to encode

                        System.out.print("Enter a phrase to encode: ");

                        String phrase = scanner.nextLine();

                        // calling function add_letters and printing encoded word

                        System.out.println("Your encoded word is: "

                                    + add_letters(number, phrase));

                  }

                  // if option is decode

                  else if (userOption == 'd') {

                        // prompt for number

                        System.out.print("Enter a number between 1 and 5: ");

                        int number = Integer.parseInt(scanner.nextLine());

                        // repeat until number is valid

                        while (true) {

                              // if number is valid

                              if (number >= 1 && number <= 5) {

                                    break;

                              }

                              // if number is not valid

                              else {

                                    System.out.println("Try Again...");

                                    // prompt for number

                                    System.out.print("Enter a number between 1 and 5: ");

                                    number = Integer.parseInt(scanner.nextLine());

                              }

                        }

                        // prompt for phrase to decode

                        System.out.print("Enter a phrase to decode: ");

                        String phrase = scanner.nextLine();

                        // calling function remove_letters and printing decoded word

                        System.out.println("Your decoded word is: "

                                    + remove_letters(number, phrase));

                  }

                  // if option is quit

                  else if (userOption == 'q') {

                        break;

                  } else

                        System.out.println("Try Again...");

            }

      }

}

/*OUTPUT*/

(e)ncode, (d)ecode, (q)uit:

e

Enter a number between 1 and 5: 4

Enter a phrase to encode: hello world

Your encoded word is: hyaemenGpMlhWuYlgfwOoESnt RPQwwiOoqokjttrbwWrlDZTRdofOr

(e)ncode, (d)ecode, (q)uit:

d

Enter a number between 1 and 5: 4

Enter a phrase to decode: hyaemenGpMlhWuYlgfwOoESnt RPQwwiOoqokjttrbwWrlDZTRdofOr

Your decoded word is: hello world

(e)ncode, (d)ecode, (q)uit:

e

Enter a number between 1 and 5: 6

Try Again...

Enter a number between 1 and 5: 1

Enter a phrase to encode: java

Your encoded word is: jdaMvEam

(e)ncode, (d)ecode, (q)uit:

d

Enter a number between 1 and 5: 1

Enter a phrase to decode: jdaMvEam

Your decoded word is: java

(e)ncode, (d)ecode, (q)uit:

q