Question

Loops | Methods | Arrays(programming language java) in software (ATOM)

Write a toolkit that includes some common functions a user might want or need

• An encryption/ decryption method. Both methods should take in a String (the String that needs to be changed), and an encryption value. The methods need to change the String by the value
• Write a method that takes an integer array as an argument. The method should return the sum of all of the elements
• Write a method that checks if an array contains a specific number

All user input should be in the main method. Arrays can be randomly generated, but Strings, values, and search values should be collected from the user
** Array length can be hard-coded or user input

** Array can be hard-coded [ 1, 4, 6, 87, 43, 56 ], use (int)Math.random(0, 100), or user input

Checklist

• Encryption method (3)

Decryption method (3)

• • String and value are hard-coded (-1 in each method)
• sum method (2)
  • Loops aren't generic (-1)
• arrayContains method (2)
  • search value is hard-coded (-1)

Answer 1

import java.util.Scanner;
import java.lang.Math;
public class Main
{
public static String encrypt(String input)
{
String output="";
for(int i=0;i<input.length();i++)
{
char ch = input.charAt(i);
ch=(char)(((int)ch+3)%128);
output=output+ch;
}
return output;
}
public static String decrypt(String input)
{
String output="";
for(int i=0;i<input.length();i++)
{
char ch = input.charAt(i);
ch=(char)(((int)ch+125)%128);
output=output+ch;
}
return output;
}
public static int sum(int[] array)
{
int sum=0;
for(int i=0;i<array.length;i++)
{
sum=sum+array[i];
}
return sum;
}
public static boolean isExists(int[] array,int number)
{
for(int i=0;i<array.length;i++)
{
if(array[i]==number)
{
return true;
}
}
return false;
}
   public static void main(String[] args)
   {
       Scanner sc = new Scanner(System.in);
       System.out.print("Enter the size of array: ");
       int size = sc.nextInt();
       int[] array = new int[size];
       for(int i=0;i<size;i++)
       {
       array[i]=(int)(Math.random()*100);
       }
       System.out.print("Array: ");
       for(int i=0;i<size;i++)
       {
       System.out.print(array[i]+" ");
       }
       System.out.println();
       System.out.println("Sum = "+sum(array));
       System.out.print("Enter the number to search in array: ");
       int temp=sc.nextInt();
       if(isExists(array,temp))
       {
       System.out.println("Found");
       }
       else
       {
       System.out.println("Not found");
       }
       System.out.print("Enter the string to encrypt: ");
       sc.nextLine();
       String input=sc.nextLine();
       System.out.println("Encrypted: "+encrypt(input));
       System.out.println("Decrypted: "+decrypt(encrypt(input)));
   }
}

input Enter the size of array: 10 Array: 24 23 44 31 77 32 34 20 72 97 Sum = 454 Enter the number to search in array: 34 Found Enter the string to encrypt: Hello World Encrypted: Khoor#Zruog Decrypted: Hello World ... Program finished with exit code 0 Press ENTER to exit console.