A less readable rendition of FizzBuzz.

fizzbuzz.js

var f = function (n) {
    var s = "";
    // 0 is falsy, the ternary then evaluates to the value right of the colon
    s += n % 3 ? "" : "Fizz";
    s += n % 5 ? "" : "Buzz";
    // empty string is also falsy
    return s ? s : n;
};

console.log(f(7));
console.log(f(12));
console.log(f(20));
console.log(f(30));