fused.java

import java.util.Scanner; 
public class fused
{
    void encode()
    {
        //calling Scanner class
        Scanner sc = new Scanner(System.in);

        //prompting user to enter a string 
        System.out.println("please enter a string");
        String s = sc.nextLine();

        //declaration and initialisation 
        String result = "" ; 

        //loop to CopyOfencode the character
        for(int i = 0  ; i < s.length() ; i++ )
        {
            char ch = s.charAt(i);
            int temp = ch + 3 ; 

            if(ch == '?')
            {
                temp = 63; 
            }
            else if( ch == ' ')
            {
                temp = 32 ; 
            }
            else if(Character.isUpperCase(ch))
            {
                if(temp > 90)
                {
                    temp = temp - 26 ;
                }
                else if (temp < 65)
                {
                    temp = temp + 26 ;
                }
            }
            else if(Character.isLowerCase(ch))
            {
                if(temp > 122)
                {
                    temp = temp - 26 ;
                }
                else if(temp < 97 )
                {
                    temp = temp + 26 ;
                }
            }
            result = result +(char)temp;
        }

        //declaration 
        String reverse = "" ; 

        // reversng the code
        for(int i = 0; i < result.length(); i++)
        {
            char ch = result.charAt(i); 
            reverse = ch + reverse; 
        }

        //displat statement 
        System.out.println(reverse);
    }

    void decode()
    {
        //calling Scanner class
        Scanner sc = new Scanner(System.in);

        //prompting user to enter a string 
        System.out.println("please enter a string");
        String s = sc.nextLine();

        // declaration and initialisation 
        String r = "" ; 

        //declaration 
        String reverse = "" ; 

        // reversng the code
        for(int i = 0; i < s.length(); i++)
        {
            char ch = s.charAt(i); 
            reverse = ch + reverse; 
        }

        s = reverse; 

        //loop to encode the character
        for(int i = 0  ; i < s.length() ; i++ )
        {
            char ch = s.charAt(i);
            int temp = ch - 3 ; 

            if(ch == '?')
            {
                temp = 63; 
            }
            else if(ch == ' ')
            {
                temp = 32 ; 
            }
            else if(Character.isUpperCase(ch))
            {
                if(temp > 90)
                {
                    temp = temp - 26 ;
                }
                else if (temp < 65)
                {
                    temp = temp + 26 ;
                }
            }
            else if(Character.isLowerCase(ch))
            {
                if(temp > 122)
                {
                    temp = temp - 26 ;
                }
                else if(temp < 97 )
                {
                    temp = temp + 26 ;
                }
            }
            r = r + (char)temp ; 
        }

        //display statement
        System.out.println(r);
    }

    public static void main(String args[])
    {
        fused obj = new fused();
        Scanner sc = new Scanner(System.in); 

        while(true)
        {
            System.out.println("1. Encode\n2. Decode");
            int option = sc.nextInt(); 

            if(option == 1)
                obj.encode(); 
            else if(option == 2)
                obj.decode(); 
        }
    }
}