How to ignore spaces in String?

July 29, 2022

I’m trying do a code where transform a String into a "Dancing string". My code are working but I want ignore spaces " ", how can I do it?

Example:

Scanner input:
Hello Guys

Output:
Dancing sentence: HeLlO GuYs

I want this output: " HeLlO gUyS"

 import java.util.Scanner;


public class Main {
     String retorno="";
     
    Main(){
    }
String    concatena(String frase){
      String[] split = frase.split("");

    for(int i =0; i<split.length;i++){
         if(i%2==0){
         retorno +=split[i].toUpperCase();
        }
       else 
         retorno +=split[i].toLowerCase();
       }
         return retorno;
    }

    public static void main(String[] args) {
        Main teste = new Main();
        System.out.println("Write the dancing sentence: \n");
       Scanner scanner = new Scanner(System.in);
      teste.concatena(scanner.nextLine());
        System.out.println("Dancing sentence: "+teste.retorno);

    }
}

>Solution :

(i%2==0) doesn’t have a way of considering a space on subsequent iterations, so could introduce a boolean and do something like this:

boolean toUpper = true;
for(int i =0; i<split.length;i++){
    if(split[i].equals(" ")) {
        retorno += split[i];
    } else if (toUpper) {
       retorno +=split[i].toUpperCase();
       toUpper = false;
    } else {
       retorno +=split[i].toLowerCase();
       toUpper = true;
   }
}