Write a java program to String Encryption.

Encryption of String using Java. Write a program to encrypt the given string. Let “Old” be a string, its encrypted form would be “Ple”. Let us see the rules to encrypt the string.

String Encryption in Java using First Approach

Rules to Encrypt String

• Replace the characters at odd positions with the next character in the alphabet.
• Leave the characters at even positions unchanged.
• If an odd position character is ‘z’ replace it by ‘a’.
• Assume the first character in the string is at position 1.

Input and Output Format

• Input is an original string.
• The output is an encrypted string.

Sample Input 1:

curiosity

Sample Output 1:

dusipsjtz

Sample Input 2:

zzzz

Sample Output 2:
Azaz

String Encryption in Java

Following are the steps to perform string encryption in Java:

• Input a string.
• Pass the string to stringFormatting() method.
• Inside the method, Create a string buffer with no character in it.
• Iterate over the string and perform the following operation:
  • Retrieve each character from the i^th position, and check if the character is at an odd position, then add 1 to its ASCII value and append it to the string buffer. Else, just append it without changing.
  • If the user input is ‘z’, then just subtract 25 from the ASCII value and append it to the string buffer.
• At last, just return the string.

import java.util.Scanner;

public class Main {
public static void main(String[] args) {
  Scanner sc = new Scanner(System.in);
  String s1 = sc.nextLine();

System.out.println(stringFormatting(s1));
}
public static String stringFormatting(String s1) {
StringBuffer sb=new StringBuffer();
for(int i=0;i<s1.length();i++){
char c=s1.charAt(i);
if(i%2==0){
if(c==122)
c=(char) (c-25);
else{
c=(char) (c+1);}
sb.append(c);}
else
sb.append(c);}
return sb.toString();
}
}

Output

String Encryption in Java using Second Approach

Here, we will encrypt the character with the next two characters. Like for example, if a user enters the string “OLD” then the encrypted form would be “QNF”.

Input and Output Format

• Input is an original string.
• The output is an encrypted string.

Sample Input 1:

old

Sample Output 1:

qnf

Sample Input 2:

dcshbch2651561

Sample Output 2:
feujdej4873783

Program to encrypt a string in Java

Following are the steps to perform string encryption in Java:

• Input a string.
• Pass the string to encryptString() method.
• Inside the method, convert the string to a character array.
• Iterate over an array, add 2 to each character and print them.

package com.date;

import java.util.Scanner;

public class Practice {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();
        encryptString(str);
    }

    private static void encryptString(String str) {
        char c[] =str.toCharArray();
       for(char c1 : c){
           c1 = (char) (c1 + 2);
           System.out.print(c1);
       }
    }
}

Output

Thus, in this way, you can encrypt the string based on the above approaches.