function numVowels (str) {
    let count = 0;

    // Define a vowels array
    let vowels = ['a', 'e', 'i', 'o', 'u'];

    // Iterate over each character in the string
    for (let i=0; i<str.length; i++) {
        // check whether this character (in lower case) is a, e, i, o, or u (converting in lower case would reduce the amount of conditons by half since there would be no need to check A, E, I, O or U)
        if (vowels.indexOf(str[i].toLowerCase()) >= 0) {
            count++;
        }
    }

    // Print and return the number of vowels
    console.log(`The number of vowels in ${str} is = ${count}`);
    return count;
}