Toggle Each Word in String Using Java

You can change the cases of the letters of a word using toUpperCase() and toLowerCase() methods.

Split each word in the string using the split() method, change the first letter of each word to lower case and remaining letters to upper case.

Example

Live Demo

public class Sample{
   public static void main(String args[]){
      String sample = "Hello How are you";
      String[] words = sample.split(" ");
      String result = "";
      for(String word:words){
         String firstSub = word.substring(0, 1);
         String secondSub = word.substring(1);
         result = result+firstSub.toLowerCase()+secondSub.toUpperCase()+" ";
      }
      System.out.println(result);
   }
}

Output

hELLO hOW aRE yOU