Appending a string at the end of each word of an input string in Java

I'm relatively new to Java but I'm trying my best to get a hold of it!

So in my assignment, I was asked to get an input from the user(string) and append a word to the end of every word of the input String. I'm probably missing something because I can't figure out something so simple.

For example, we get the input from the user

This is how I like it

And I would like it as:

Thismeow ismeow howmeow Imeow likemeow itmeow

I can not use any if/for/while statements/loops in the solution of this problem, however, I'm allowed to use Java String Class API

This is the code I have so far

public class Exercise2 {

    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);

        System.out.println("Please enter a string : ");
        String userString = scan.nextLine();

        String inputString = "meow";

        //I'm aware that for the next like concatenating is just adding
        //the word meow with the last word of the userString.
        String newString = userString.concat(inputString);

        scan.close();
    }
}

Question: How do I get the desired output?

Solution

This question has a number of answers already, but as far as I can say, none of them get it right. Either it does not work with multiple spaces (as every space is replaced with "meow "). Or multiple spaces are repaced with "meow " - thus spaces or lost. Or space at the end (or absence thereof) is not handled correctly.

So here's my take:

    String userString = "This is  how   I    like    it";
    System.out.println(userString.replaceAll("([^\\s])(\\s|$)", "$1meow$2"));

Results in:

Thismeow ismeow  howmeow   Imeow    likemeow    itmeow

I assume that "word" is a sequence of non-space characters delimited by space characters or beginning or end of the string. Then last character of the "word" is a non-space character which is immediately followed by a space character or end of string. This can be detected by a regex ([^\s])(\s|$). First group will represent the last character of the word, second group - the following space or end of string.

So to append meow to each word we could insert it between the last character of the word and the following space/end of string. This is what $1meow$2 does. $1 references the first group from regex (last character of the word), $2 - the second group (following space/end of string).

Meow.