Happy Number

happy_number.js

var isHappy = function(n) {

    var arr = n.toString().split('');
    var times = 0;
    var exp;

    var scan = function(arr) {

        exp = 0;
        times += 1;

        if (times > 10) {

            return false;

        }

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

            exp += Math.pow(arr[i], 2);

        }

        if (exp === 1) {

            return true;

        } else {

            arr = exp.toString().split('');

            return scan(arr);
        }

    }

    return scan(arr);

};