title: Java-toggle alphabet case in string
body: <p>I have my code to switch the case from upper to lower and vice versa. I also have it to where it will toggle upper to lower, and lower to upper. My question is; is there a way I can get it to also include the character such as a comma or a period. For example, if I type in the string "Hello, there." I will get: "HELLO, THERE.", "hello, there" and "hELLOTHERE". How can I get it to where my third output will say "hELLO, THERE."</p>
  
  <pre><code>import java.util.*;
  public class UpperLower2
  {
  
      public static void main(String[] args)
      {
          System.out.println("Enter in a sentence:"); 
          Scanner input = new Scanner(System.in); 
          String sentence = input.nextLine();
  
  
          System.out.println("All uppercase:" + sentence.toUpperCase());
          System.out.println("All lowercase:" + sentence.toLowerCase()); 
          System.out.println("Converted String:" + toggleString(sentence)); 
          input.close(); 
       }
  
      public static String toggleString(String sentence)
      {
         String toggled = ""; 
         for(int i=0; i&lt;sentence.length(); i++)
         {
  
  
             char letter = sentence.charAt(i); 
  
             if(Character.isUpperCase(sentence.charAt(i)))
             {
                  letter = Character.toLowerCase(letter); 
                  toggled = toggled + letter; 
  
             }
             else if(Character.isLowerCase(sentence.charAt(i)))
             {
                 letter = Character.toUpperCase(letter);
                 toggled = toggled + letter; 
             }
  
         }
         return toggled; 
  
     }
  </code></pre>
  
  <p>}</p>