Putting a space in a string

Question

Assuming I have a String like "MikeJackson" I am trying to figure out a way to put a space in between so it becomes "Mike Jackson". And then applying the same method to another string say "JohnBull" would give me back "John Bull". This is the code I came up with:

public class Test{

    public Test(){

    }
public void sep(String s){
    s = s + " ";
   char[] charArray = s.toCharArray();
   int l = s.length();
for (int i = 0; i < l; i++){
    char p = ' ';

    if(Character.isUpperCase(s.charAt(0))){
        continue;   
    }
    else if (Character.isUpperCase(s.charAt(i))){
        int k = s.indexOf(s.charAt(i));
        charArray[l] = charArray[--l];
        charArray[k-1] = p;
    }
    //System.out.println(s.charAt(i));
}
}
    public static void main (String args[]){

    Test one = new Test();

    one.sep("MikeJackson");
    }  
}

My idea was to add a space to the String so that "MikeJackson" becomes "Mike Jackson " and then shift the characters on place to the right (check for where I find an uppercase) ignoring the first uppercase. Then put a character ' ' in place of the character 'J' but shift 'J' to the right. That's what I was trying to achieve with my method but it looks I need some guidelines. If anyone could help. Thanks.

Answer 1

Try this:

"MikeJackson".replaceAll("(?!^)([A-Z])", " $1");

For every upper char I am adding a space before.

Also, it works with multiple uppercase words. I am getting Word1 Word2 Word3 for Word1Word2Word3.

Answer 2

public static void sep(String s) {
    StringBuilder result = new StringBuilder();
    for (int i = 0; i < s.length(); i++) {

        result.append(s.charAt(i));
        if (i != s.length() -1 && Character.isUpperCase(s.charAt(i + 1))) {
            result.append(" ");
        }
    }
    System.out.println(result);
}

Simply add a space if the next character is uppercase.