Toggle the String Using JAVA

Answer:

KboatChangeCase - Java Code

import java.util.Scanner;

public class KboatChangeCase
{
    public static void main(String args[]) 
    {
        Scanner in = new Scanner(System.in);
        System.out.println("Enter a string:");
        String str = in.nextLine();
        int len = str.length();
        String rev = "";

        for (int i = 0; i < len; i++) 
        {
            char ch = str.charAt(i);
            if (Character.isLetter(ch))
            {
                if (Character.isUpperCase(ch))
                {
                    rev += Character.toLowerCase(ch);
                }
                else
                {
                    rev += Character.toUpperCase(ch);
                }
            }
            else
            {
                rev += ch;
            }
        }
        
        System.out.println(rev);

    }
}

OUTPUT

Change Case (Uppercase ↔ Lowercase)