[Javascript] Create alphanumeric code

gistfile1.txt

export const alphanumeric = (len) => {
    const str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
    return [...Array(len)].reduce(
        (a) => a + str[~~(Math.random() * str.length)],
        ""
    );
};

console.log(alphanumeric(6)); // HNF2RU