JavaScript FizzBuzz

fizzbuzz.js

// first naive, straight-forward solution:

function divides(a,b) {
    return a % b === 0;
}

for (i=1; i<20; i++) {
    if (divides(i,3) && divides(i,5)) {
        console.log("fizzbuzz");
    } else if (divides(i,3)) {
        console.log("fizz");
    } else if (divides(i,5)) {
        console.log("buzz");
    } else {
        console.log(i);
    }
}

// now onto a more functional approach:

function divides(a,b) {
    return a % b === 0;
}

function range(n) {
    return [...Array(n).keys()];
}

function fizzbuzz(range, rules) {
    return range.map( i =>
        rules.reduce( (acc, rule) => acc + rule(i), '') || i
    ) 
}
    
const rules = [
    x => divides(x, 3) ? 'fizz' : '',
    x => divides(x, 5) ? 'buzz' : '' 
]

console.log( fizzbuzz( range(20), rules ));