Reverse words in place

reverse-words-in-place.js

/**
 * Your team is scrambling to decipher a recent message, worried it's a plot to break into a major European National Cake Vault. 
 * The message has been mostly deciphered, but all the words are backward! Your colleagues have handed off the last step to you.
 * 
 * Write a function reverseWords() that takes a message as a string and reverses the order of the words in place.
 * 
 * string message = "cake pound steal";
 * reverseWords(message);
 * cout << message << endl;
 * // prints: "steal pound cake"
 */

let reverseWords = (str="") => {
    let words = str.split(" ");

    // built-in approach
    // words = words.reverse();
    // words = output.join(" ");
    // return words;

    // or.. with out using another data structure
    str = "";

    for (let i=(words.length-1); i >= 0; i--) {
        str += words[i];
        if (i != 0) {
            str += " ";
        }
    }
    return str;
}

const runner = () => {
    console.log(`Expecting: 'steal pound cake'; Answer? ${reverseWords("cake pound steal")}`);
};

runner();