function vowels(word) {
    var w = word;
    var count = 0;
    for (var i = 0; i < word.length; i++) {
        if (w[i] === "a" || w[i] === 'e' || w[i] === 'i' || w[i] === 'o' || w[i] === 'u') {
            count++;
        }
    }
    return count;
}
console.log(vowels('unbelievable'));

var consonant = function (text) {
    var vowels = ['a', 'e', 'i', 'o', 'u'];
    var count = 0;

    for (var i = 0; i < text.length; i++) {

        var letter = text[i];
        if (vowels.indexOf(letter) === -1) {
            count++;
        }
    }
    return count;
};
console.log(consonant("zebra"));