ISC COMPUTER SCIENCE PRACTICAL 2017 QUESTION 3 CAESAR ENCRPTION

public class ISC2017Q3 {

       public static void main(String[] args) {

             String msg;

             Scanner in = new Scanner(System.in);

             System.out.println("INPUT the text to be encrypted:");

             msg = in.nextLine();

             while(msg.length()< 3 || msg.length() > 100) {

                    System.out.println("Invalid Input, try again:");

                    msg = in.nextLine();

                    }

             Caesar obj = new Caesar(msg);

             System.out.println("OUTPUT:");

             obj.encryptionProcess();

             System.out.println();

             obj.displayEncryptedText();

             in.close();

             }

}

class Caesar {

public void displayEncryptedText() {

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

             System.out.print(text_to_array[i]);

       }

public void encryptionProcess() {

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

             if((text_to_array[i] >= 'A' && text_to_array[i] <= 'Z') || (text_to_array[i] >= 'a' && text_to_array[i] <= 'z') ) {

                    if(text_to_array[i] >= 'A' && text_to_array[i] <= 'Z')

                          text_to_array[i] = shiftPlaces(text_to_array[i],true);

                    if(text_to_array[i] >= 'a' && text_to_array[i] <= 'z')

                          text_to_array[i] = shiftPlaces(text_to_array[i],false);

                    } // end-if

             } // end-for

       }

private char shiftPlaces(char c,boolean flag) {

       if(flag==true)

             return ((char)(c+13 > 90 ? (65+c+12-90):c+13)); // shifting 13 places in A-Z

       else

             return ((char)(c+13 > 122 ? (97+c+12-122):c+13)); // shifting 13 places in a-z

       }

Caesar(String msg){

       text_to_encrypt = msg;

       text_to_array = new char[text_to_encrypt.length()];

       text_to_array = text_to_encrypt.toCharArray(); // using library function- converting string to char array-

       }

// you can use for loop and string_name.charAt(i) method to extract character from string one by one

private char[] text_to_array;

private String text_to_encrypt;

}