Change calculator

JavaScript

function coins(amount) {
    return [1,2,5,10,20,50,100,200,500,1000].map(function (coin) {
        return [~~ (amount / coin), amount %= coin][0];
    });
}

function coins2(amount) {
    const res = {};
    const currency = [1,2,5,10,20,50,100,200,500,1000].sort(function(a, b) {  return b - a;});
    currency.map(function (coin) {
        res[coin] = Math.floor(amount / coin);
        amount = amount % coin;
    });
    return res;
}

console.log(coins2(1045).filter(n => n));
console.log(coins2(578));
console.log(coins2(20));
console.log(coins2(1));