Bingo random number picker

bingo.js

const Bingo = (function(){
    const pool = [];
    for(let i=0; i<79; i++) {
        pool.push(i+1);
    }

    function next() {
        const index = Math.round(Math.random() * (pool.length - 1));
        return pool.splice(index, 1)[0];
    }

    return {
        next: next
    };
})();